Turkey’s president has attacked what he called “Israeli terrorism” after the Gaza office for the Turkish state-run news agency was destroyed during the latest round of hostilities between Israeli forces and Palestinian militants.

More than 24 hours of heavy fire continued into Sunday, as militants launched rockets out of the strip and Israel responded with air attacks. Israeli Prime Minister Benjamin Netanyahu said he had ordered the military to launch more “massive strikes” on Gaza and move tanks, artillery and infantry to the edge of the enclave.

“We strongly condemn Israel’s attack against Anadolu agency’s office in Gaza,” Recep Tayyip Erdoğan said on Twitter. “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.”

The Israel Defense Forces said it had bombed a building in Gaza City on Saturday containing Hamas military intelligence and general security offices.

During the weekend, more than 430 rockets and mortars had been fired out of Gaza, which Israel said it responded to with 200 air and tank strikes. One Israeli civilian and six Palestinians, including two militants, had been killed, officials on both sides said.

The dead in Gaza included a pregnant woman and her 14-month-old niece, medics said, in the most recent of violent exchanges that have erupted on a near-monthly basis for the past year. Israel denied on Sunday that its forces had killed the woman and infant, saying they were hit by accidental militant fire. Authorities in Gaza had originally identified them as mother and daughter but the family later clarified the woman was the baby’s aunt.

A Palestinian relative of fourteen-month baby girl Seba Abu-Arrar carries her body during her funera in the Al-Zaitun neighborhood in the east of Gaza City. Photograph: Haitham Imad/EPA

The latest round began on Friday after a Palestinian Islamic Jihad sniper fired at Israeli troops, wounding two soldiers, according to the Israeli army. Israel responded with an airstrike that killed two members of Hamas, another faction that controls the strip. Israel says it holds Hamas accountable for all activity in Gaza.

On the same day, Israeli forces killed two Palestinians demonstrating near the frontier, and on Saturday morning militants began rocket barrages that stretched into Sunday. The launches have often followed killings at rallies on the border, where Palestinians have been calling for an end to a debilitating Israeli-Egyptian blockade that has led to a dire humanitarian crisis.

Egypt has led a UN-backed effort to mediate a longer ceasefire between the two sides but repeated attempts have only won temporary lulls in the tit-for-tat conflict. Hamas and Islamic Jihad released a joint statement saying: “Our response will be broader and more painful if the enemy pursues its aggression.”

In southern Israel, air-raid sirens sent families fleeing to shelters. Dozens of projectiles were incepted by the country’s Iron Dome system, but several slipped through, hitting residential neighbourhoods and in one case, a school. Four Israelis, including an 80-year-old woman, were wounded.

Israelis stand outside their building after it was hit by a rocket fired from Gaza in the costal city of Ashkelon. Photograph: Tsafrir Abayov/AP

Residents in Gaza City said explosions caused by Israeli strikes thundered throughout the night. Fireballs lit up the sky as several-story buildings crumbled in on themselves.

The escalation comes as Israel prepares to host the high-profile Eurovision song contest in Tel Aviv. That week will also mark the one-year anniversary since Israeli snipers killed nearly 60 Palestinians protesting at the frontier.

The Associated Press contributed to this report