They were allegedly planning to detonate a car bomb in the city, kidnap soldiers, shoot at army road blocks, plant bombs at soldiers' gathering points, stab armed Jews and take over an Israeli bus.
The latest arrests are part of a crackdown on the militant group. Last Wednesday, Israel said it seized about thirty activists in the Bethlehem area in the West Bank. Israeli forces have killed four Hamas guerrillas since April.
Hamas has been badly hit by the arrest of 3,500 members this year, and by harassment in Gaza from Yasser Arafat's Palestinian Authority. A Hamas official in Gaza was quoted as saying: "Hamas is now facing an internal crisis. Its leaders are not sure of themselves anymore. They cannot decide on what course they need to take."
The armed cells of Hamas and Islamic Jihad were never numerous and their notoriety came from spectacular suicide bomb attacks, notably two inside Israel in Tel Aviv last October and at Beit Lid in January.
Since then, there have been no bombings in Israel, although both organisations have attacked soldiers guarding settlements in the Gaza Strip.
Mr Arafat has insisted that no more attacks be made in or around Gaza and his efforts have been praised by senior Israeli army officers.
Mr Arafat clearly expects to be rewarded by an Israeli pull-out from the main population centres on the West Bank.
Despite the setbacks, Hamas and Islamic Jihad enjoy the support of at least 20 per cent of the Palestinian population, according to polls. Among the 100,000 Palestinians in Hebron, hatred is particularly strong because of the presence of 7,000 militant Israeli settlers. Hebron was the scene of the slaughter last year of 29 worshippers at the Ibrahimi mosque by Baruch Goldstein, from the nearby settlement of Kiryat Arba.
Hamas claimed yesterday that Israeli bulldozers buried one of its men alive during the siege of a house in Hebron last week. Hamas has called on the Red Cross to investigate the incident.
Hamed Yaghmour, 22, a member of the armed wing of Hamas, which has carried out suicide bombings, died in an 11-hour siege last Friday. In a letter to the Red Cross, Hamas said: "They started firing anti-tank rockets and then moved remote-controlled bulldozers to destroy the house completely, which led to burying Yaghmour alive under the rubble."
The Israeli army says Yaghmour belonged to an Izzedin al Qassem cell, the military strike-force of Hamas, based in Hebron, and was involved in the killing of at least six Israelis.
The army says he was shot dead when he was cornered in the house after he refused to surrender. The house was then bulldozed. On 16 April, three other members of the same Hamas unit were ambushed and killed by Israeli border police in a grove near Hebron.Reuse content