Israeli air strikes kill 18 in Gaza reprisals

At least 18 people in the Gaza Strip were killed in Israeli air strikes over the weekend and dozens wounded as 120 rockets and mortar shells were fired from Gaza into Israel in the most violent exchange since Israel's incursion into the Gaza Strip two years ago.

Israel said those hit in Gaza were militants, including rocket teams and senior Hamas commanders, but Hamas said civilians were among the casualties.

The strong Israeli attacks were touched off by the demolition on Friday of an Israeli school bus by an anti-tank missile fired from Gaza. Most of the children had just been dropped off but the one student still aboard was critically wounded.

A Hamas official later said "it was not known that the bus carried schoolchildren". Israeli officials said the bus, a bright yellow, was on its daily rounds and clearly visible from Gaza.

Israel's newly deployed anti-rocket system, Iron Dome, was reported to have downed eight of the Katyusha rockets fired at the cities of Ashkelon and Beersheba, a success that reportedly surprised even military officials. The Israeli-developed system is the first in the world to successfully interdict short-range rockets in mid-flights.

Israel said it had received a call from Hamas leaders transmitted through UN officials for a ceasefire. It said it would call off its attacks if Hamas did. Mounting rocket attacks by Hamas in recent weeks have led to calls by residents of Israeli towns in the area for another massive ground attack into Gaza. However, if the Iron Dome system can provide a sense of security a ground operation is unlikely.

Israel would prefer not having the Arab world, presently in turmoil, seize on an incursion into Gaza to achieve internal unity by rallying against Israel. In particular, Israel does not want to endanger its still tentative relations with the new military regime in Egypt.

Hamas officials and the Palestinian Authority called on the Arab League to intervene. Hamas also called on Egypt "to restrain the Israeli aggression and protect the Palestinian people".

Hamas has begun to use powerful, long-range anti-tank missiles acquired from Iran against Israeli military vehicles on the fringe of the Gaza Strip. Two months ago, Israel deployed tanks equipped with a newly developed anti-missile system capable of detonating incoming missiles before they hit. One Israeli official said that the ensuing frustration may have led Hamas to target the school bus.

In an air attack on a car this weekend, a leader of Hamas' military wing, Tayser Abu Snima, 29, was killed. Israel says he had been "physically involved" in the capture five years ago of Israeli soldier Gilad Shalit who is still being held in Gaza.

Israeli officials report a conflict within Hamas between its political wing in the Gaza Strip and Damascus on the one hand, which want to halt the present cycle of violence, and the military wing in Gaza which does not.