BEIRUT, Lebanon, AP -Nearly 400 Lebanese soldiers have deployed near the Syrian border after Lebanon demanded a militant Palestinian group hand over members who killed a Lebanese contractor, a security official said Wednesday.

The official said dozens of elite commandos supported by tanks are among the deployment, which started moving into place late Tuesday near the remote southeastern village of Helweh, a few miles from the Syrian border.

The pro-Syria Fatah Uprising group has a training base in Helweh and members of the group on Tuesday allegedly shot dead Mohammed Ismail, a civilian contractor working for the Lebanese army, said the official, who spoke on condition of anonymity because he was unauthorized to speak to the media.

Lebanese authorities are calling on the group to hand over those who killed the contractor, the official said.

But Fatah Uprising, one of several Damascus-based radical Palestinian factions with bases in Lebanon, has so far declined to turn any of its members over, claiming the group did not kill the contractor, the official added.

It was unclear if the Lebanese army plans to storm the militant group's base, which is on the edge of the village of Helweh and just a half mile from the border with Syria.

Fatah Uprising broke with the mainstream Palestinian Fatah faction in 1983 and is led by the Syrian-based Col. Saeed Moussa, better known as Abu Moussa.

Tension has increased along the Lebanese-Syrian border since Syria withdrew its troops from Lebanon in April, ending a 29-year military presence, amid the crisis that followed the Feb. 14 assassination of ex-Lebanese Prime Minister Rafik Hariri.

Lebanon has alleged in recent weeks that pro-Syrian Palestinian guerrillas have brought weapons into this country with the aim of causing disturbances. The Palestinians have denied the accusations.

The pressure on Syria is likely to intensify Wednesday when a report by the U.N. special envoy on Syria-Lebanon, Terje Roed-Larsen, on disarming Lebanese militias is released.

At a summit in Paris last week, Lebanese Prime Minister Fuad Saniora and Palestinian President Mahmoud Abbas condemned the smuggling of arms to Palestinian militants in Lebanon and discussed disarming Palestinians living here.