EREZ CROSSING, Gaza Strip - A Palestinian woman suicide bomber has struck at the main border crossing between Israel and the Gaza Strip, killing four Israelis and wounding seven people.

Militant group Hamas, which claimed joint responsibility for the attack along with the al-Aqsa Martyrs Brigades, vowed to escalate attacks in a more than three-year-old uprising.

The woman, identified by Hamas as a 22-year-old mother of two, blew herself up in a terminal where Palestinian labourers from the fenced-in Strip were being put through Israeli security checks before entering a nearby industrial complex.

"Glass and black smoke flew everywhere. Arabs were screaming, Jews were screaming," said a Palestinian witness, her clothes stained with the blood of others.

A senior Israeli army officer said the dead included soldiers and least one Israeli civilian. Security sources said four Palestinians were among the wounded.

It was the first Palestinian suicide attack since a December 25 bombing that killed four Israelis near Tel Aviv, and raised further doubts about the prospects for reviving a US-backed peace "road map" stalled by persistent violence.

A caller to Reuters' office in Gaza claimed joint responsibility for the bombing in the name of the militant Islamic group Hamas and the al-Aqsa Martyrs Brigades, an armed offshoot of President Yasser Arafat's Fatah movement.

Hamas, the main group behind a campaign of suicide bombings during three years of violence, said it sent a woman for the first time because of growing Israeli security "obstacles" facing its male bombers.

The move could pose new dangers to the Jewish state, which has already been hit several times by woman bombers dispatched by smaller militant groups.

"Resistance will escalate against this enemy until they leave our land and homeland," Hamas founder and spiritual leader Sheikh Ahmed Yassin told Reuters in Gaza.

Witnesses said the bomber, identified by Hamas as 22-year-old Reem Al-Reyashi from Gaza City, was limping when she set off a metal detector operated by Israeli security personnel at the Erez crossing.

"She managed to hoodwink the soldiers by saying she had a metal surgical implant," Israeli Brigadier-General Gadi Shamni, commander of Israeli forces in the Gaza Strip, told reporters.

"Because she was a woman, a female soldier was sent for to search her. She used this opportunity to enter the building, a metre or two past the door, and blow up," he said.

"I thought my ears were exploding," said a Palestinian woman labourer who had been standing nearby.