"We received 20 fatalities and several wounded after an Israeli air strike targeted a house belonging to the Hassan family in Al-Nuseirat refugee camp in central Gaza," the Al-Aqsa Martyrs Hospital said in a statement.

Witnesses said the strike occurred around 3:00 am local time. The Israeli army said it was checking the report.

Palestinian official news agency Wafa reported that the wounded included several children, and rescuers were searching for missing people trapped under the rubble.

Fierce battles and heavy Israeli bombardments have been reported in the central Nuseirat camp since the military launched a "targeted" operation focussing on the southern city of Rafah in early May.

Palestinian militants and Israeli troops have also clashed in north Gaza's Jabalia camp for days now.

Witnesses said several other houses were targeted in air strikes during the night across Gaza, and that air strikes and artillery shelling also hit parts of Rafah during the night.

The Israeli military said two more soldiers were killed in Gaza the previous day.

The military said 282 soldiers have been killed so far in the Gaza military campaign since the start of the ground offensive on October 27.