Hezbollah leader Hassan Nasrallah said Tuesday that Syrian rebels will not be able to defeat President Bashar Assad's regime militarily, strongly suggesting that Syria's "real friends" including his Iranian-backed militant group would intervene on the government's side if the need arises.

The powerful Shiite Muslim group is known to be backing Syrian regime fighters in Shiite villages near the Lebanon border against the mostly Sunni rebels fighting to topple Assad. But the comments by Nasrallah were the strongest indication yet that his group was ready to get more substantially involved to rescue Assad's embattled regime.

"Syria has real friends in the region and in the world who will not allow Syria to fall in the hands of America or Israel or the Takfiris," he said, referring to followers of an al-Qaida like extremist ideology.

Hezbollah and Iran are close allies of Assad. Both have been accused by rebels of sending fighters to assist Syrian troops trying to crush the 2-year-old Syrian uprising as it morphed into a civil war.

Nasrallah said Tuesday that now there are no Iranian forces in Syria, except for some experts who he said have been in Syria for decades. But he added: "What do you imagine would happen in the future if things deteriorate in a way that requires the intervention of the forces of resistance in this battle?"

Hezbollah has an arsenal that is the most powerful military force in Lebanon, stronger than the national army. Its growing involvement in the Syrian civil war is already raising tensions inside the divided country and has drawn threats from enraged Syrian rebels and militants.

Nasrallah also said his fighters had a duty to protect the holy Shiite shrine of Sayida Zeinab, named for the granddaughter of Islam's Prophet Muhammad's, south of Damascus.

He said rebels were able to capture several villages around the shrine and gunmen were deployed hundreds of meters (yards) away from the shrine who have threatened to destroy it.

"If the shrine is destroyed things will get out of control," Nasrallah said citing the 2006 bombing of the Shiite al-Askari shrine in the Iraqi city of Samarra. That attack was blamed on Al-Qaida in Iraq and set off years of retaliatory bloodshed between Sunni and Shiite extremists that left thousands of Iraqis dead and pushed the country to the brink of civil war.

Nasrallah also said that accusations that the regime has used chemical weapons were an attempt to justify foreign intervention in Syria.

While there has been growing speculation about Hezbollah's role in the conflict next door, the violence inside Syria has raged on, including in the capital, where a powerful bomb on Tuesday ripped through a bustling commercial district, killing at least 14 people.

The blast shattered store fronts, set cars ablaze and brought Syria's civil war to the heart of Damascus for the second consecutive day.

On Monday, Syrian Prime Minister Wael al-Halqi narrowly escaped an assassination attempt after a car bomb targeted his convoy as it drove through a posh Damascus neighborhood. The bombings appear to be part of an accelerated campaign by opposition forces to hit Assad's regime in the heavily defended capital.

Open gallery view Iranian President Mahmoud Ahmadinejad, Syrian President Bashar Assad and Hezbollah chief Hassan Nasrallah meeting in Damascus on February 25, 2010. Credit: AP