Israeli troops killed a Palestinian youth early on Monday, as a widespread West Bank manhunt for three missing Israeli youths entered its fourth day.

Ahmad Arafat, 19, was shot dead near the West Bank city of Ramallah as Israeli soldiers were conducting arrests as part of efforts to locate the three teens, which Israel said were kidnapped near Hebron on Thursday.

Israeli Prime Minister Benjamin Netanyahu has accused the Islamist Hamas movement of snatching the youths, and placed responsibility for their safe return on the shoulders of Mahmoud Abbas and his Palestinian authority, which recently formed a unity government with Hamas.

Palestinian medical and security sources said Arafat was shot in the chest during clashes with Israeli army forces in the Jelazoun refugee camp.

The Palestinian security sources could not immediately say whether the army had intended to arrest Arafat. They noted he had been released from an Israeli prison one week ago.

The Israeli army could not immediately comment on the Jelazoun shooting, but said it was continuing its campaign of detaining dozens of Palestinians throughout the West Bank as part of its efforts to locate the missing youths.

The youths, one of whom also holds a US passport, are students at Jewish seminaries in the West Bank. Israeli authorities say they went missing late on Thursday while hitching in an area between Bethlehem and Hebron.

Israeli troops have arrested more than 150 Palestinians, most of them from Hamas, over the past four days. Among those detained were 10 Hamas members of the long-defunct Palestinian parliament.

Israeli military operations were focused on the southern West Bank Hebron area but increased military presence was felt throughout the entire territory.

The disappearance of the three Israeli youths came 10 days after the establishment of a new Palestinian government of technocrats pieced together by Abbas' Fatah movement and Hamas following a unity agreement between rival leaders in the West Bank and Gaza. The reconciliation with Hamas enraged Israel, which describes the group as a terrorist organization.

Early on Monday, Israeli war planes carried out strikes on alleged terrorist targets in Gaza. Medical sources in Gaza said two Palestinians were injured in the strikes targeting Hamas and Islamic Jihad facilities.

AP-AFP