Government officials decided Monday to increase strikes against Hamas in Gaza and call up additional troops, as southern Israel braced for expanded rocket fire following the deaths of several terror operatives in Gaza overnight.

On Monday evening, Hamas fired more than 60 rockets into Israel between 8 and 9 p.m., to a range of some 40 kilometers — including Ashdod, Ashkelon, Gan Yavneh, and the outskirts of Beit Shemesh. Seven people were treated for shock, initial reports said, but there were no reports of serious injury. What were described as false alarms sounded in the Jerusalem and Etzion Bloc areas.

IDF spokesman Lt. Col. Peter Lerner said the military had called up 1,500 reserves troops, mostly from the Home Front Command and Iron Dome air defense crews, and deployed two additional conscripted infantry brigades, Paratroops and Givati, to the border with the Palestinian enclave Monday. The army, Lerner said, was still in a defensive position but has shifted its readiness in order to address an escalation in the ongoing conflict with the Gaza Strip.

Though ministers did not decide on a ground incursion or large scale operation, they warned one could be in the offing if rocket fire did not cease, Israeli media reported.

The decision followed the death of some six Hamas members overnight, in what the military said was a “work accident,” when an explosive-laden tunnel that was hit in an Israeli airstrike several days earlier exploded.

Three other terror operatives were reported killed in other Israeli strikes.

On Monday afternoon, senior ministers in Israel’s security cabinet voted to instruct the IDF to increase air raids against targets in Gaza, following a meeting in Jerusalem.

Ministers warned that the increase in violence could bring rocket fire to the Gush Dan region of central Israel, news site NRG reported. The area, which includes the heavily populated cities of Tel Aviv and Rishon Lezion, last saw rocket fire in 2012 during Operation Pillar of Defense.

Residents in areas within 40 kilometers of Gaza, including Ashdod and Beersheba, were instructed not to hold any large gatherings and to stay near bomb shelters.

Egyptian efforts to broker a ceasefire have been scaled back, meanwhile, The Times of Israel was told.

Lerner said within the army there is now “a preparedness for escalation,” in contrast to last week when the IDF wished to convey a message of a defensive deployment.

The move to bolster troops outside Gaza and increase Israeli operations against the Strip came after several days of intense Palestinian rocket fire. The military said Monday afternoon that some 50 projectiles had been launched at Israel in the course of the day, adding to dozens shot the day before. The major barrage of 60 rockets, deeper into Israel, came later in the evening.

Most landed in open areas and several were shot down by the Iron Dome anti-missile system. Lerner said Hamas was behind most of the rocket fire in recent days.

Israeli planes have run almost nightly sorties against targets in Gaza and earlier this week forces hit a tunnel in Gaza that was about to be used for an attack against Israel, Lerner said.

Hamas operatives attempted to access that tunnel overnight Sunday, “and they meddled with their own explosives,” causing a detonation that led to their deaths, Lerner said.

“We understand that there is a potential of escalation” on account of the deaths, he said.

A senior military official told the Ynet news site that the tunnel had been at the center of Israeli military activities against the Strip for several days. It was not clear if the tunnel crossed the Gaza-Israel border, as other subterranean passages destroyed by the IDF  in recent years have.

The military said the tunnel had been constructed by Hamas in order to “execute complex terror attacks” against Israel.

It was the fourth such offensive terror tunnel that the IDF has detected over the past 18 months, the army said.

Israelis have been gearing up for a possible escalation for several weeks, amid a marked uptick in rocket fire following an Israeli crackdown on Hamas in the wake of the abduction and killing of three Israeli teens in the West Bank last month.

Military officials say about 200 rockets have been fired at southern Israel since the start of the operation.

Tensions have also ratcheted up following the killing of an Arab teen in Jerusalem by suspected Jewish extremists in an apparent revenge attack last week, leading to riots in the capital and several Arab towns.

Israeli officials have warned in recent days of a possible escalation against Hamas should rocket fire persist.

Earlier Monday, a Hamas official said it would not agree to a ceasefire unless detainees arrested in the crackdown were released. The group also released a video calling on “settlers” in the southern Israeli town of Beersheba to “flee before it is too late.”

On Saturday night, Hamas warned it could hit any Israeli city with its missiles.