BEIRUT: Syrian rebels said they have detained 13 Hezbollah members and threatened to take the fight to the Hezbollah stronghold in Beirut’s southern suburbs unless the party ended its support for Bashar Assad’s regime, an FSA spokesman said.

“We [vow] to take the battle in Syria to the heart of the [Beirut] southern suburbs if [Hezbollah] does not stop supporting the killer Syrian regime,” Fahd al-Masri told pan-Arab Asharq al-Awsat in an interview published Tuesday.

He said the FSA is holding 13 Hezbollah members in a village near Homs for involvement in the Syria conflict.

“They [Hezbollah detainees] have confessed to killing and slaughtering [people] in Syria,” Masri said, pointing out that most of the captives hail from Baalbek and Hermel in east Lebanon’s Bekaa Valley.

Masri stressed that Hezbollah is “deeply involved” in the Syria fighting, warning that the fate of the 13 detained men was “in the hands of [FSA] field commanders.”

Hezbollah “is involved in the killing of the Syrian people and in suppressing the revolution, particularly in Damascus and Homs,” Masri said.

“Hezbollah focuses [its operations] on Damascus’ Zabadani area given that the Iranian Revolutionary Guard has a military base there,” he said. “They also have a huge presence in Qusair and Talbisa.”

Responding to Masri's comments, Hezbollah bloc MP Kamel Rifai denied that members of the resistance group were being sent to fight alongside the Syrian army.

“The party has a basic rule that forbids fighting anyone other than Israel and thus it bans its elements from fighting in Syria,” Rifai told The Daily Star Tuesday.

"There are Shiites living in Syria, but that does not make them Hezbollah [fighters]," he added.

In apparent response to Rifai, Masri told the Lebanese MTV channel later Tuesday that the 13 Hezbollah men were arrested in their military uniforms.

“They were armed and in military uniform when they were captured in Homs’ countryside,” Masri said. “They were not pilgrims and not on a political tour.”

He held Hezbollah fully responsible and said the Shiite group “must” not drag Lebanon into lost battles.”

Recent reports claim that Hezbollah fighters are involved in the 18-month-old Syria crisis and that a number of them have been killed in fighting there.

“Funerals were held for four Hezbollah members who died at a military training camp as well as three others who passed away in the Nabi Sheet explosion. None of them were involved in the Syrian fighting as has been rumored,” Rifai said.

Last week, Hezbollah said three of its fighters were killed in an explosion at a munitions depot in Nabi Sheet, east Lebanon.

On Monday, Hezbollah buried one its fighters who a security source said was killed in the border area with Syria.

Hussein Abdel Ghani al-Nimr, 35, "died while he was performing his jihadist duty," a Hezbollah spokesman said.

Nimr’s death comes less than a week after a senior Hezbollah commander, who Syrian rebels said was killed in Syria, was buried in the Bekaa.

Hezbollah has announced several similar burials in past months, without revealing details about the deaths.