Israeli Prime Minister Benjamin Netanyahu on Sunday promised to continue “massive strikes” in response to rockets fired from the Gaza Strip, reported Reuters.

“I instructed the [military] this [Sunday] morning to continue its massive strikes on terror elements in the Gaza Strip,” Netanyahu said. He has ordered “tanks, artillery and infantry forces” to reinforce troops deployed near Gaza.

Tensions started flaring up since Friday when clashes were reported from the Gaza border. Four Palestinians, including two Hamas militants, were killed after two Israeli soldiers were wounded in a shooting. On Saturday, Hamas and Islamic Jihad fired around 450 rockets into Israel.

The escalation happened after Hamas sought further concessions from Israel under a ceasefire. The truce, brokered by Egypt and the United Nations, has seen Israel allow Qatar to provide financial aid to Gaza.

Authorities in Gaza said six people were killed, including at least two militants, by Israeli strikes on Saturday. The Gaza health ministry said the Israeli strikes also wounded 47 people. Islamic Jihad identified two of the deceased as its militants.

But Israel blamed the firing by Hamas for the deaths of a pregnant mother and her 14-month-old baby. “Their unfortunate death was not a result of [Israeli] weaponry but a Hamas rocket that was fired and exploded not where it was supposed to,” Israeli Army spokesperson Jonathan Conricus told AFP.

The Israeli Army said it has struck some 220 militant targets in Gaza. Two multi-storey buildings in Gaza City were destroyed. Israel said one of the buildings housed Hamas military intelligence and security offices. The other building housed Hamas and Islamic Jihad offices, said Israel.

Turkey claimed its state news agency Anadolu had an office in one of the buildings, reported The Guardian. “We strongly condemn Israel’s attack against Anadolu agency’s office in Gaza,” Recep Tayyip Erdoğan tweeted. “Turkey and Anadolu agency will continue to tell the world about Israeli terrorism and atrocities in Gaza and other parts of Palestine despite such attacks.”

Egyptian and United Nations officials asked “all parties to immediately de-escalate”. The European Union called for an immediate halt to rocket fire from Gaza. The United States condemned Gaza militants and extended it support to Israel’s “right to self-defence against these abhorrent attacks”.