Rocket fire and air strikes rattled a tense Gaza ceasefire at the weekend after a week of violence after the Israeli killing of a senior member of the Islamic Jihad Movement. Israel on Saturday targeted positions in Gaza following rocket fire into Israel, the army said, despite a ceasefire coming into force on Thursday. Air defences intercepted the rockets, the Israeli military said. While no group has claimed credit for the attack, it comes four days after Israel killed a top commander in the Islamic Jihad, Gaza’s second most powerful armed group after Hamas. The killing sparked the latest tit-for-tat rocket attacks and air strikes with Israel. Hamas has been spared much of the latest attacks from Israel that have killed 34 people — including civilians. On Thursday, the Israeli military said it made a mistake when it killed a family of eight as it targeted a building in Gaza the day before. Israel said that its assessment showed the building was empty. The Palestinian Health Ministry said that the Al Sawarkah family were killed, including three children and two toddlers. Israeli media quoted local residents saying the family had no connection to the Islamic Jihad but were simple sheepherders. But Palestinian security sources said the Israeli strikes on Saturday were aimed at two Hamas sites in the north of the territory. "Among the sites targeted was a military camp of the Hamas terror organisation and a military compound used by the Hamas naval forces," a statement from the Israeli military said. "In addition, an underground terror infrastructure was also targeted." There were no reports of casualties. That strike triggered almost immediate retaliatory rocket fire from Islamic Jihad, which set off air-raid sirens and sent Israelis rushing to bomb shelters in the country's southern and central regions. The Israeli military said around 450 rockets were fired at its territory during the fighting and air defences intercepted dozens of them. The military responded with air strikes it said targeted Islamic Jihad militant sites and rocket- and missile-launching squads. There have been three wars since 2008 between Israel and Palestinian militants in the blockaded territory that is home to about two million people. Israeli analysts said that the focus on Islamic Jihad rather than Hamas earlier this week was a clear signal that the army sought to avoid a major new conflict. Israel usually holds Hamas responsible for all actions carried out by groups operating in its territory. Hamas repeatedly said it would not abandon its ally, but keeping out of the fighting helped it maintain a fragile truce with Israel that has seen tens of millions of dollars in Qatari aid flow to the group in Gaza since last year. Israeli Prime Minister Netanyahu came under fire from political rivals at home for not holding Hamas accountable for attacks from the territory it rules. The violence came at a politically sensitive time for Israel, with no new government in place since a September election ended in deadlock. On Thursday, Israeli military spokesman Jonathan Conricus told reporters that the army had "wanted to keep Hamas out of the fighting". "Throughout the operation, we, of course, distinguished between Hamas and Islamic Jihad, and all of our operations were measured, proportionate and focused only on military assets belonging to Islamic Jihad," he said.