Nine Palestinians were injured late Friday when Israeli warplanes struck three separate targets in the Gaza Strip, which is ruled by the Islamic Hamas movement, medics and witnesses said.

The witnesses said they heard three successive explosions in western Gaza City in a strike aimed at a training compound belonging to Hamas security forces.

Medical sources said at least nine Palestinian police men were injured at the Hamas police training compound. They were taken by ambulances to the city's main Hospital Shifa.

Hamas security sources said that the Israeli jet carried out two other airstrikes on eastern and southern Gaza Strip, in which no injuries were reported. The sources said the military planes targeted an empty area in eastern Gaza Strip and smuggling tunnels dug under the border area between Gaza Strip and Egypt.

The successive Israeli airstrikes came several hours after a Russian-made Grad rocket was fired from the Gaza Strip at the southern costal Israeli town of Ashkelon. Damage was reported, but there were no injuries.

The Popular Resistance Committee, a pro-Hamas militant group in Gaza claimed responsibility for the attack, saying that the Arab League decision to resume the direct peace talks with Israel 'is absurd and useless'.