An Irishwoman has been wounded in a gun battle between Israeli forces and Palestinian gunmen in a refugee camp in the northern West Bank city of Jenin.

Caoimhe Butterly of Palestinian Solidarity told RTÉ News that she was wounded while serving as a human shield to protect children; she was hit in the leg.

In a separate gun battle in the same camp earlier, a British UN worker, Ian Hook, was shot dead.

Prime Minister Ariel Sharon told Israeli security forces to hit militants hard as his troops swept the West Bank in retaliation for yestderay's bombing that killed 11 in Jerusalem.

'I have given the orders and told security forces to take all necessary measures to strike those who hit us,' Sharon said. 'Such is the government's policy and it will be executed,' he said.

Israeli forces launched incursions into the Gaza Strip and the West Bank city of Bethlehem overnight.

In Bethlehem, troops sealed off the Church of the Nativity to prevent militants taking refuge in the compound as they did during Israel's reoccupation of the city in April.

The move follows yesterday's suicide bomb attack in Jerusalem in which 11 people were killed.