Hezbollah forces are entering Syria and helping forces there suppress anti-government protests, Israel Radio quoted a Lebanese parliament member as saying on Sunday.
The parliament member, speaking to a Lebanese radio station, said that the Lebanese army can not prevent this from happening. He noted that the Syrian army has, like the Hezbollah troops, breached the border with Lebanon.
There is a fear that Syrian forces will attempt to kidnap refugees who fled to Lebanon to escape violence from the Syrian government, the parliament member said.
On Saturday, the Washington Post reported that Iran had been sending trainers and advisers to assist Syrian President Bashar Assad's violent crackdown on protesters.
Iran has sent members of its elite Quds force, whom the United States has recently sanctioned in response to the 10 weeks of brutal Syrian government quashing of protests, to help the Syrian government, Iran's most important ally in the region, the Washington Post reported.
Manpower is only one of the forms of assistance Iran has sent to Syria, the report said, with the Islamist government sending weapons, riot gear and sophisticated surveillance equipment that allows Syrian authorities to trace and find opposition members through Facebook and Twitter accounts.
In the most recent violence in Syria, a human rights group said security forces shot dead 12 demonstrators during protests against Baath Party rule on Friday.
The Syrian National Organization for Human Rights said "the authorities are still pursuing the calculated course of using excessive violence and live ammunition to confront mass demonstrations.
The group said the killings occurred in rural districts around Damascus, in southern Syria, the northwestern province of Idlib, the coast and the central city of Homs. Activists on Friday had put the death toll at eight.
Rights groups estimate at least 1,000 civilians have been killed by security forces, the army and gunmen loyal to President Assad over 10 weeks.
They said 10,000 people have been arrested, with beatings and torture a common tactic.