Israeli warplanes struck several targets in southern Gaza Strip early on Friday, Palestinian witnesses said, adding they heard three explosions and the buzz of the warplanes which flew over the enclave.

Palestinian inspect the site of a destroyed factory after an Israeli airstrike in Gaza City. [Xinhua/AFP]

The Israeli airstrikes came in response to an earlier homemade rocket attack carried out by Gaza militants.

Israeli Radio reported that a rocket fired from Gaza landed at Hof Askol in southern Israel, but there have been no reports of casualties.

The witnesses said three air-to-ground missiles were fired at targets west of the southern Gaza Strip city of Khan Younis and one missile was fired at a target in Rafah town near Gaza Strip and Egypt's border.

Israeli warplanes also struck a target in southern Gaza City, the witnesses said, adding the targeted areas are used by militant groups for training.

Hamas security sources in Gaza said the Israeli warplanes targeted posts which belong to Palestinian militant groups in southern Gaza Strip towns of Rafah and Khan Younis and in Gaza City, adding that no casualties were reported.

Meanwhile, Israeli Apache helicopters struck another target west of the central Gaza Strip refugee camp of Nuseirat, no injuries were reported.