Syria's defence ministry on Sunday accused Lebanon's Hezbollah group of abducting three soldiers to Lebanon and killing them there, state media reported, as Hezbollah denied any involvement in clashes.

"A group from the Hezbollah militia kidnapped three members of the Syrian army on the Syrian-Lebanese border before taking them to Lebanese territory and eliminating them," the news agency SANA quoted the defence ministry as saying.

"The defence ministry will take all the necessary measures after this dangerous escalation from the Hezbollah militia," it added, saying the incident occurred near the Zeita Dam, west of Homs.

Meanwhile, Hezbollah in a statement denied any involvement in clashes with Syrian security forces or in Syrian territory.

The group said it "categorically denies any connection to the events taking place today on the Lebanese-Syrian border."

It added that it "reaffirms its previous announcements that Hezbollah has no relation to any events within Syrian territory."

Lebanon's state news agency NNA reported that rockets fired from Syrian territory had landed in the Lebanese village of Qasr near the border.

"A number of rockets, fired from the Qusayr countryside inside Syrian territory, fell on the border town of Qasr," it said, without providing further details.

A Lebanese security source told AFP that "tensions began after three Syrian general security personnel crossed into Lebanese territory at the village of Qasr, where they were shot at by local gunmen affiliated with a family involved in smuggling."

The source said the reason they entered was unknown.

After their death, "the gunmen handed over their bodies to the Lebanese army which in turn handed them over to the Syrian side."

NNA also reported that the bodies of three Syrian soldiers had been handed over to Syria via the Lebanese Red Cross.

The source said "an escalation subsequently occurred by Syrian security forces, who shelled homes in Qasr."

Hezbollah was a key backer of Syria's former president Bashar al-Assad before he was toppled in a lightning offensive by Islamist-led rebels in December.

The country's new authorities announced last month the launch of a security campaign in the border province of Homs, aimed at shutting down routes used for arms and goods smuggling.

They accused Hezbollah of launching attacks, saying it was sponsoring cross-border smuggling gangs.