Israeli forces yesterday sealed off parts of the West Bank while Palestinian security forces arrested scores of Hamas supporters after four settlers were gunned down ahead of Middle East peace talks.

Furious settlers vowed to flout a moratorium on settlement construction in protest at the attack as tension rose ahead of a Washington summit hosted by US President Barack Obama to relaunch peace talks suspended in 2008.

Israeli soldiers carried out house-to-house searches in villages in the Hebron area, near the Kiryat Arba settlement where the two couples, including a pregnant woman, were killed on Tuesday.

Access routes to the city of Hebron were closed by military roadblocks.

Hamas, which claimed responsibility for the attack, said Palestinian security forces had arrested more than 150 of its members.