Gaza City/Tel Aviv  - Israel bombed Gaza City's main security compound, which houses a central prison and several security forces headquarters, Sunday morning, killing four people, on the second day of an offensive against the Islamic Hamas movement.

The latest deaths bring to 282 the number of Palestinians, many of them militants, killed since Israel began the offensive shortly before noon on Saturday morning. Over 900 people have been wounded.

Prisoners were seen scrambling over the rubble and fleeing the security compound after the Israeli strike.

Israeli aircraft have struck over 22 times since midnight, after the Israel Air Force hit more than 100 targets in Saturday's sorties.

Palestinian militants fired over 20 missiles at Israel Sunday morning, including two his struck south of the port city of Ashdod, a distance of around 30 kilometres from the Gaza Strip's northern border, and the furthest the militants' missiles have ever struck in Israel.

There were no casualties reported in the missile strikes, which bring to around 100 the number of rockets and mortar shells launched at the Jewish state since the operation against Hamas began, and to around 300 the number fired since a six-month truce between Israel and the Gazan militias ended 10 days ago, on December 19.

Israel opened its air offensive against Hamas positions in the Strip late Saturday morning, in response to the massive rocket and mortar barrages Hamas and other militant groups launched at southern Israeli towns and villages since the end of the truce.

Israeli officials, from Prime Minister Ehud Olmert down, said Saturday that "Operation Cast Lead" was not limited by time constraints and was designed to bring about an end to the rocket fire from the Gaza Strip. (dpa)