At least seven Palestinians were killed and six others injured in an Israeli raid on the Gaza Strip town of Beit Lahiya.  The Israeli military says tank fire was targeted at militants preparing to shell Israelis, but Palestinian witnesses say the casualties were civilian farmers.

The Israeli army said it fired in response to mortar attacks by Palestinian militants that injured one Israeli working in the Erez industrial zone and two others when a shell exploded near an Israeli school bus.

The bodies of eight Palestinians can be seen at the morgue in the town of Beit Lahiya

According to Palestinian witnesses the dead and wounded Palestinians were farmers working in a strawberry field. The Israeli military said a tank fired two shells at nine masked militants who had just fired two mortar shells. It said the militants were members of Hamas.

A Palestinian hospital official identified the dead by name and said that six of them were from the same family. He said the casualties ranged in age from 11 to 17. But Israeli military sources said Palestinian liaison officers identified six of the dead as being 17 or older. David Baker, an official in the Israeli prime minister's office, accused the militants of using civilians as human shields.

Palestinian presidential candidate Mahmoud Abbas told supporters at a campaign rally in Gaza that the dead were martyrs killed by, in his words, the "Zionist enemy." It was unusually harsh language for Mr. Abbas, who is considered a moderate.  He called off a planned visit to the hospital where the wounded were being treated when two powerful explosions, apparently from Israeli tanks shells, went off near his motorcade. Palestinian security officials said militants had fired two homemade rockets from near the hospital at Israeli troops.

Palestinian militants in Gaza have increased their attacks on Israeli targets in recent months in what is seen as an attempt to make it appear they are forcing the withdrawal from Gaza that Israel plans later this year. Israeli Prime Minister Ariel Sharon has warned that Israel would respond forcefully to any violence and Israeli raids into Gaza have increased accordingly.

Mahmoud Abbas has called for an end to Palestinian rocket attacks on Israel but has also said he will not use force to stop them. He has said he prefers to bring the militants into the political process and not crack down on them as Israel has demanded.