BEIRUT — Two rockets hit Hezbollah strongholds in Beirut on Sunday, tearing through an apartment and peppering cars with shrapnel, a day after the Lebanese group’s leader pledged to lift President Bashar Assad to victory in Syria’s civil war.

The strikes illustrated the potential backlash against Hezbollah at home for linking its fate to the survival of the Assad regime. It’s a gambit that also threatens to pull fragile Lebanon deeper into Syria’s bloody conflict.

Despite such risks, Hezbollah chief Hassan Nasrallah made it clear there is no turning back. In a televised speech Saturday, he said Hezbollah will keep fighting alongside Assad’s forces until victory, regardless of the costs.

For Hezbollah, it may well be an existential battle. If Assad falls, Hezbollah’s supply line of Iranian weapons through Syrian territory would dry up and it could become increasingly isolated in the region.

At the same time, Hezbollah, a Shiite Muslim group, is raising the sectarian stakes in Lebanon by declaring war on Syria’s rebels, most of them Sunni Muslims.

Lebanon and Syria share the same uneasy mix of Sunnis, Shiites, Christians and Alawites, or followers of an offshoot of Shiite Islam. In trying to defeat the rebels, Assad relies on support from minority Shiites, Christians and his fellow Alawites.

On Beirut’s beach promenade, opinions about Hezbollah’s new strategy seemed to fall along religious lines.

Mahmoud Masoud, a Sunni, said he fears Lebanon will become more unstable. “I don’t want to see everything I’ve worked for and my country fall apart of because of a certain group’s interests,” he said of Hezbollah.

Tamam Alameh, a Shiite, sided with Hezbollah. “The Syrians helped Lebanon a lot. We should help them and rid them of the conflict in their country,” he said.

The rockets struck early Sunday in south Beirut, an unusual type of attack.

One rocket hit a car dealership in the Mar Mikhael district, wounding four Syrian workers, badly damaging two cars, and spraying others with shrapnel. Part of the rocket’s main body was embedded in the ground, where a Lebanese soldier measured its diameter.

The second rocket tore through a second-floor apartment in the Chiyah district, about one mile away. It damaged a living room, but no one was hurt.