Israel conducted dozens of air strikes on the Gaza Strip on Monday, after Palestinian militants fired barrages of rockets at southern Israeli cities. The pre-dawn raids on Gaza were some of the heaviest seen since the fighting began a week ago. Israel said it hit facilities belonging to the militant group Hamas and several commanders' homes, but main roads and power lines were also damaged. There were no immediate reports of casualties following the strikes. People in Gaza have told of their fear. "I was getting ready to die. I had to be at peace with it," Najla Shawa, a Palestinian humanitarian worker and mother of two, told the AFP. "People we know [were killed], people we work with... ordinary people, professional people, young and old." The Israeli military said more than 50 warplanes conducted a 20-minute attack on the Gaza Strip shortly before dawn on Monday. They struck 35 "terror targets" and destroyed more than 15km (9.3 miles) of an underground tunnel network belonging to Hamas, it added. The military also said it had hit the homes of nine "high-ranking" Hamas commanders. Israeli soldiers also fired artillery from positions near the Gaza border. The fighting began after weeks of rising Israeli-Palestinian tension in occupied East Jerusalem that culminated in clashes at a holy site revered by both Muslims and Jews. Hamas, which controls Gaza, began firing rockets after warning Israel to withdraw from the site, triggering retaliatory air strikes. Israel says more than 3,000 rockets have been fired into the country over the past week. Later on Monday, rocket warning sirens were sounded in several areas around southern Israel. Palestinian officials in Gaza said the overnight strikes had caused widespread power cuts and damaged hundreds of homes and other buildings. One resident, Sarah Mahmoud, told the BBC: "We are still alive, but we are not well. The warplanes destroyed the most beautiful road in Gaza." The overall death toll in the territory now stands at 198, including 58 children and 34 women, with 1,230 injured, according to the Hamas-run health ministry. Israel says more than 130 militants are among the dead - but Hamas has not recognised this. Meanwhile, international calls for a ceasefire have continued to mount. Egypt's President Abdul Fattah al-Sisi said on Monday that his country was "going to great lengths to reach a ceasefire... and hope still exists". The UN Security Council held an emergency meeting on Sunday, and Secretary-General António Guterres warned that further fighting had "the potential to unleash an uncontainable security and humanitarian crisis". He pleaded for an immediate end to the "utterly appalling" violence.