The Iranian-backed guerrilla group Hizbullah is increasingly involved in the Israeli-Palestinian conflict, with orders and money flowing from its Beirut headquarters into the West Bank, according to a senior Israeli intelligence official.
The group has 10 'controllers' in Beirut who are in daily contact with Palestinian groups in the West Bank, mainly the al-Aqsa Brigades, the official said.
Hizbullah is supported by Syria as well as Iran and controls 44 cells in the Palestinian territories. They have carried out 62 attacks in which 27 Israelis have been killed and 50 injured, he said.
The claims come at a time of increasing tension between Iran and the west, mainly because of suspicion that Tehran is developing nuclear weapons. The allegations of Hizbullah involvement could be part of a softening-up process by Israel ahead of action against Iran or Syria. This week, Israeli jets flew over the Bekaa valley in Lebanon, an area controlled by Syrian forces.
Israel's claim was given some credence this week by the Palestinian leader, Yasser Arafat, who complained about Iran meddling in the West Bank and Gaza. He claimed Hizbullah was trying to 'infiltrate' Fatah, his own organisation, which includes the al-Aqsa Brigades.
Hizbullah, whose forces are ranged along the Israeli border in southern Lebanon, is the best-equipped and best-disciplined paramilitary group in the region and is respected and feared by the Israeli military. Israel pulled out of southern Lebanon in 2000 after suffering high casualties at its hands.
For the past four years, Hizbullah has been relatively quiet. It has fired an occasional Katyusha rocket across the border and engaged Israeli soldiers at Shabaa farms, an outpost where the Israeli, Lebanese and Syrian borders meet.
The intelligence official said the head of the Hizbullah operation in Beirut responsible for the West Bank and Gaza was a Palestinian in his 30s who had been born in Israel.
Until now, the Israeli-Palestinian conflict has been largely self-contained. The main Palestinian groups - Fatah, Hamas, Islamic Jihad and the Popular Front for the Liberation of Palestine - are homegrown organisations.
On the ground in Gaza, there is little sign of Hizbullah. Hamas leaders in Gaza earlier this year denied Hizbullah was active. And the Israeli intelligence official said that, although Hamas received money from Iran, it had resisted Hizbullah involvement in Gaza.
But he said it was different on the West Bank, where Israel's policy of targeted killings of the leaders of Palestinian groups had left a vacuum that Hizbullah was helping to fill, mainly within the al-Aqsa Brigades.
The official also confirmed that there was regular contact between Israeli intelligence officers and their counterparts in Mr Arafat's Palestinian Authority. Speaking to British journalists in his compound in Ramallah earlier this week, Mr Arafat said Iran's supreme leader, Ayatollah Ali Khamenei, 'is working against us and giving money to all these fanatical groups, financing Hamas and Islamic Jihad, and trying to infiltrate Fatah'.
But he disputed that Hizbullah was already operating in the West Bank and Gaza. 'Hizbullah is not active in the territories. It is trying,' he said.
Palestinian groups are relatively poorly armed, lacking the weaponry and training available to Hizbullah. The intelligence official claimed that, since June, the Palestinians had smuggled into Gaza 128 anti-tank weapons, 900 Kalashnikovs, 200kg (440lb) of explosive and five anti-aircraft missiles.