The IDF struck nearly 150 terror targets in the Gaza Strip since the beginning of a ground offensive in the Hamas-controlled enclave on Thursday night, military sources said Friday afternoon. Among the targets hit by the Israeli military were 21 rocket launchers, 4 homes of senior terrorist operatives, and several tunnels, Israel Radio reported.

IDF troops uncovered a number of tunnel openings as well; at an emergency cabinet meeting on Friday, Prime Minister Benjamin Netanyahu cited the imperative to thwart Hamas’s cross-border tunnel operations as a central reason for the resort to a ground offensive, and said the operation might have to expand in order to achieve his goal of attaining sustained quiet for the citizens of Israel.

Some 20 terrorists were so far killed in the ongoing ground operation and 13 were arrested and taken in to Israeli security facilities for questioning, according to the IDF.

One IDF soldier, Sergeant Eitan Barak, 20, from Herzliya, was killed Friday morning during an operation against rocket launchers in the area of Beit Hanoun, in the north-east edge of the Gaza Strip at about three in the morning. The force came under fire, but it was not immediately clear whether the shooting came from Hamas or, in error, from the IDF. Five other soldiers were injured, one moderately and the rest lightly. Barak will be laid to rest on Sunday.

Nonetheless, Hamas fired some 80 rockets into Israel by late afternoon.

Israel launched the operation late Thursday, following a 10-day campaign of more than 2,000 air strikes against Gaza that had failed to halt relentless Hamas rocket fire on Israeli cities.

Israel’s first major ground offensive in Gaza in just over five years came as Egyptian cease-fire efforts stalled. Earlier this week, Israel accepted Cairo’s offer to halt hostilities, but Hamas refused, demanding that Israel and Egypt first give guarantees to ease the blockade on Gaza.

This image made from video shot through a night vision scope released by the Israeli military on Friday, July 18, 2014, shows troops during the early hours of a ground offensive in the Gaza Strip.  (photo credit: AP Photo/Israeli Defense Forces)

This image made from video shot through a night vision scope released by the Israeli military on Friday, July 18, 2014, shows troops during the early hours of a ground offensive in the Gaza Strip. (photo credit: AP Photo/Israeli Defense Forces)

Israel had been reticent about launching a ground offensive for fear of endangering its own soldiers and drawing international condemnation over mounting Palestinian civilian deaths.

It remains unclear how long the offensive will last and what Israel’s eventual goal may be — other than its stated goal of stopping the rocket attacks and thwarting the Hamas tunnel operations.

Hamas has survived Israeli offensives in the past, including a major three-week ground operation in January 2009 from which it emerged militarily weaker, but in each case it recovered. The groups controls an arsenal of thousands of rockets, some long range and powerful, and it has built a system of underground bunkers.

But Hamas is weaker now than it was during the previous two offensives — from 2008-9 and 2012 — with little international or even regional support, even among traditional Gaza supporters Turkey and the Gulf-state of Qatar.

French Foreign Minister Laurent Fabius was travelling Friday to Egypt, Jordan and Israel as part of a diplomatic push to stop the fighting in Gaza.

He said in a statement that he wants a cease-fire and lasting truce “that responds to Israel’s security needs and Palestinian economic needs.”

An IDF missile hits Palestinian buildings in Gaza City on July 17, 2014. Israel launched a ground operation in Gaza late Thursday on the 10th day of an offensive to stamp out rocket attacks from the Palestinian enclave, the army said. (photo credit: AFP/THOMAS COEX)

An IDF missile hits Palestinian buildings in Gaza City on July 17, 2014. Israel launched a ground operation in Gaza late Thursday on the 10th day of an offensive to stamp out rocket attacks from the Palestinian enclave, the army said. (photo credit: AFP/THOMAS COEX)

The operation may be its best opportunity for Israel to rid the strip of the group — which much of the world considers to be a terrorist organization.

But an operation that last weeks could take a heavy toll in both casualties and cost, and most Israelis has no wish to retake Gaza, which the country effectively gave up in 2005.

Egypt supports a ceasefire, but not Hamas or its conditions, which include a lifting to the siege of Gaza and completely open borders into the Sinai — where Egypt is already fighting Islamic extremists.

Israeli defense officials said soldiers faced little resistance during the first night of the ground operation, but the longer the military keeps a presence in Gaza, the greater the risk for heavy casualties on both sides.

Forces are expected to spend a day or two staking ground and are working in the north, east and south of the Gaza Strip. Then, they are expected to move to the second phase, which is to destroy tunnels, an operation that could take up to two weeks.

After thousands of troops had been on standby for several days, Netanyahu said he ordered the military to prepare for a “significant expansion” of the ground offensive.

“Since it is not possible to deal with the tunnels only from the air, our soldiers are doing it also from the ground,” he said at the special cabinet meeting in Tel Aviv.

“We chose to begin this operation after the other options were exhausted and with the understanding that without the operation the price we will pay can be very high.”

Throughout the night, the thud of tank shells echoed across Gaza, often just a few seconds apart. Several explosions from Israeli missile strikes shook high-rise buildings in central Gaza City and sent pillars of smoke into the sky.

The wounded were rushed to Gaza’s main Shifa Hospital, including several members of the same family struck by shrapnel from tank shells. Among those hurt were a toddler and a boy of elementary school age, their bodies pocked by small bloody wounds.

Gaza health officials said at least 20 Palestinians have been killed since the ground operation began, including three teenage siblings killed by shrapnel from a tank shell attack. It was not immediately clear if the 17 terrorists killed by the IDF were among the casualties reported by Gaza authorities.

Palestinian missiles are fired from Gaza City toward Israel following Israeli air strikes on July 17, 2014.  (Photo credit: AFP/ Thomas Coex)

Palestinian missiles are fired from Gaza City toward Israel following Israeli air strikes on July 17, 2014. (Photo credit: AFP/ Thomas Coex)

“The ground offensive does not scare us and we pledge to drown the occupation army in Gaza mud,” Hamas spokesman Sami Abu Zuhri said in a statement.

Since the July 8 start of the air campaign, more than 260 Palestinians have been killed and more than 2,000 wounded, Palestinian health officials said. In Israel, one civilian died and several were wounded.

Israeli public opinion appears to strongly support the offensive after days of unrelenting rocket fire from Gaza and years of southern Israeli residents living under the threat. Gaza terrorists have fired more than 1,500 rockets at Israel over the past 11 days.

Israel said it launched an open-ended assault on several fronts, with the primary aim being to destroy underground tunnels into Israel built by Hamas that could be used to carry out attacks.

On Thursday, 13 heavily armed Hamas terrorists tried to sneak in through such a tunnel, but were stopped by an airstrike after they emerged some 250 meters (820 feet) inside Israel.

Prior to the Israeli cabinet meeting, several ministers said they expected a prolonged offensive.

“We need to go in and finish the job. We need to eliminate every terrorist. They have no immunity.” said Uri Ariel, a Cabinet minister from the hard-line Jewish Home party.

Copyright 2014 The Associated Press