After one of the quietest years on the Gaza front in recent memory, the first month of the new year saw a drastic increase in attacks originating from the coastal enclave, according to the security services.

In January, government figures show, Gaza-based terror groups fired three times as many rockets at Israel as during an average month in 2013. These included 20 mortar and rocket attacks on Israel’s southern communities, two improvised explosive devices (IEDs) set off on the Gaza-Israel border and two incidents where the IDF stopped militants attempting to launch rockets.

Most of the attacks were carried out by fringe groups operating in Gaza who sought to undermine the Hamas regime, the security establishment determined, according to Israeli daily Maariv.

While Hamas has refrained, for the most part, from directly attacking Israel in order to avoid another invasion, it has also been less proactive in preventing attacks, which it had previously done with relative success after Egypt helped mediate a ceasefire to end operation “Pillar of Defense” in November 2012.

Hamas withdrew most of the 900-strong force it employs along the Israel-Gaza border in order to prevent rocket fire into Israel and “safeguard public order.”

Sources in Gaza told The Times of Israel the decision of Hamas’s military wing to withdraw most members of the rocket-prevention force, which was first deployed last July, was taken in the wake of Israel’s airstrikes on targets in Gaza overnight Thursday. Those strikes were ordered in response to a rocket attack on the southern city of Netivot on Thursday.

Last week, in the wake of several incidents of rocket fire into Israel, Defense Minister Moshe Ya’alon warned Hamas that it would “pay a heavy price” for such attacks. “If [Hamas] doesn’t know how to impose its authority on terrorist organizations operating from its territory we will continue to act to make it, and those who are active in terror and fire at Israel, pay a heavy price,” he said.

Intelligence Minister Yuval Steinitz said Saturday that the Israeli military could invade the Gaza Strip and topple its Hamas government if the rocket fire continued. ”If the drip of rockets from Gaza continues, we will have no choice but to go inside [Gaza] in order to eliminate Hamas, and allow the Palestinian Authority to regain control of the Gaza Strip,” Steinitz said.

The anti-rocket force was established last July. It numbered 600 men at first, operating round the clock, but was more recently bolstered to 900, underlining Hamas’s desire to avoid an escalation of violence with Israel. The order withdrawing most members of the force thus appears to represent a shift in Hamas tactics.

On Friday, two Grad rockets were fired from the Sinai Peninsula at the southern city of Eilat. The Iron Dome missile defense system shot down at least one of them. An al-Qaeda-linked terrorist group that operates in the Sinai and Gaza, Ansar Bayt al-Maqdis, claimed responsibility. The group said in a statement that the rocket attack was prompted by “the cooperation between Egypt and Israel and the bombing of Gaza residents.”

Avi Issacharoff contributed to this report.