Israeli military strikes in the Gaza Strip have killed at least 70 people over the last day, Palestinian medics said on Saturday, as mediators launched a new ceasefire push to end the 15-month-old war.

At least 17 of those who died were killed in airstrikes on two houses in Gaza City, the first of which destroyed the home of the Al-Ghoula family in the early hours, medics and residents said.

"At about 2 a.m. we were woken up by the sound of a huge explosion," said Ahmed Ayyan, a neighbor, adding that 14 or 15 people had been staying in the house.