Israeli Prime Minister Benjamin Netanyahu said he has ordered "massive strikes" in the Gaza Strip after a two-day surge in cross-border attacks that killed six Palestinians and one Israeli.Israeli warplanes and gunboats continued to target the Gaza Strip on Sunday, as dozens of rockets were also fired from Gaza into southern Israel.The Palestinian victims included a pregnant mother and her one-year-old baby. In the Israeli city of Ashkelon, a 58-year-old Israeli man was killed in a rocket strike. "This morning I instructed the IDF (Israel Defence Forces) to continue with massive strikes against terrorists in the Gaza Strip," Netanyahu, who doubles as Israeli defence minister, said in a statement after consulting with his security cabinet on Sunday."I also instructed that forces around the Gaza Strip be stepped up with tank, artillery and infantry forces."Hamas is responsible not only for its attacks against Israel, but also for the Islamic Jihad's attacks, and it is paying a very heavy price for it," he added. Armed factions in Gaza, otherwise known as the Joint Operations Room, which include the military wing of Hamas and the Islamic Jihad, vowed on Saturday to "extend its response" if the Israeli army continued to target the strip."Our response will be broader and more painful in the event [Israel's] extends in aggression, and we will remain the protective shield of our people and our land," the Joint Operations Room said in a statement.Al Jazeera's Harry Fawcett,reporting from the Israeli side of the fence with Gaza, said the escalation is "far from over"."This is potentially a dangerous and long, major military escalation," he said. "The Israeli media is quoting senior defence sources as saying they expect this fighting to last some days."Israeli media reported Gaza fighters over the past two days fired more than 400 rockets at towns and cities in southern Israel and that Israeli Iron Dome anti-missile system had intercepted more than 250 of them.The government media office in Gaza said Israeli warplanes carried out about 150 raids, in addition to artillery shelling targeting 200 civilian landmarks in the Gaza Strip, including residential buildings, mosques, shops and media institutions.About 70 Palestinians were wounded in the attacks, according to Gaza's health ministry.Gaza resident Um Alaa Abu Absa spent Sunday picking up broken glass and debris inside her property in the aftermath of the air raids."There was a lot of bombing, the neighbours were affected a lot, the street scene was indescribable, people were afraid and terrified and running, and everyone was looking for their children, nobody was able to see others," Abu Absa said.One of the buildings destroyed had housed the Gaza bureau of the Turkish state-run Anadolu news agency."We call on the international community to act swiftly in order to ease tensions that have increased due to Israel's disproportionate actions in the region," said a Turkish Foreign Ministry statement. On Sunday, the Israeli army denied that Falastine Abu Arar, the 37-year-old pregnant mother, and her infant daughter Siba, were killed by Israeli forces, instead blaming a misfiring of a Palestinian rocket.Two Palestinian men, 22-year-old Imad Nseir and 25-year-old Khaled Abu Qaleeq, were also killed by Israeli air raids on Saturday night.The Palestinian Islamic Jihad group said the two men killed overnight on Sunday, Mahmoud Issa, 26 and Fawzi Bawadi, 23, were members of its armed wing.'Dangerous escalation'The United Nations Special Coordinator for the Middle East Peace Process Nickolay Mladenov called on all parties to "immediately deescalate and return to the understandings of the past few months"."I am deeply concerned by yet another dangerous escalation in Gaza and the tragic loss of life," he said."My thoughts and prayers go out to the family and friends of all those who were killed, and I wish a speedy recovery to the injured."The latest flare-up came after four other Palestinians were killed in two separate incidents on Friday.Two of them were shot dead during the weekly Great March of Return protests near the Israeli fence east of Gaza, while an air raid targeting a Hamas outpost killed two members of the movement's armed wing.The Israeli army said the air raid was in response to a shooting that wounded two of its soldiers near the fence.An Israeli drone attack near a vehicle, which injured three Palestinians, preceded the barrage of rockets fired, our correspondent said. Israel and Egypt have maintained a crippling blockade on Gaza since Hamas seized control of the territory in 2007.Following heavy fighting in late March, Israel agreed to ease the blockade in exchange for a halt to rocket fire. This included expanding a fishing zone off Gaza's coast, increasing imports into Gaza and allowing the Gulf state of Qatar to deliver aid to the cash-strapped territory.However, Israel has not delivered on these agreements, and scaled back the expansion of the fishing zone at the end of April."Various reported understandings about easing economic restrictions, creating jobs, looking to improving electricity flow in Gaza – there's been nothing on those lines," Harry Fawcett said.About two million Palestinians live in Gaza, whose economy has suffered from years of a blockade as well as recent foreign aid cuts. Unemployment stands at 52 percent, according to the World Bank, and poverty is rampant.Israel has waged three offensives on Gaza since December 2008.The last war in 2014 severely damaged Gaza's already weak infrastructure, prompting the United Nations to warn that the strip would be "uninhabitable" by 2020.