Israeli tanks and planes intensified their bombardment of northern Gaza, as well as Khan Younis and Rafah in the south of the enclave, residents, authorities and media said.

Four people, including two children, were killed and several others wounded in an Israeli air strike on a house in Khan Younis early on Friday, Reuters quoted Palestinian health officials as saying.

Official Palestinian news agency Wafa said overnight Israeli airstrikes on Khan Younis and Rafah killed or injured tens of people. One of the strikes hit a housing block near the Kuwaiti hospital in Rafah, Wafa added.

Live video footage looking into southern Gaza from Israel after dawn on Friday showed thick, black plumes of smoke rising into the air. The cause of the smoke was not immediately known.

A US security envoy had talks with Israel about shifting its strategy in Gaza toward surgical operations against Hamas and away from a broad ground campaign, as Palestinians reported heavy attacks along the narrow coastal strip on Friday.