Clashes shocked the Syrian capital of Damascus on Sunday after rebels and jihadist militants launched a surprise attack as the country struggles to find a peaceful end to its six-year civil conflict.

Fighters tried to make their way to the city center, trading fire with government forces that could be heard across Damascus.

The UK-based Syrian Observatory for Human Rights (SOHR) said that the violence began "with two car bombs and several suicide attackers" in the Jobar district in the east of the city. Rebels seized several buildings in the area before being pushed back as they attempted to take a bus station.

SOHR chief Rami Abdel Rahman said the rebels were seeking to "link their territory in Jobar with Qabun to break the government siege there." Qabun is an area in northeastern Damascus that has been the target of heavy shelling by government forces in recent weeks.

State television reported that the army had "tightened the noose around terrorist groups besieged in the industrial zone on the northern edges of Jobar."

Ceasefire talks to no avail

Control of Jobar has been divided between moderate rebels, government troops, and jihadists for more than two years.

As forces loyal to Syrian President Bashar al-Assad have made significant gains all around the country in recent months, they have focused on regaining control of the entirety of the capital. Beyond shelling and airstrikes, the government has offered "reconciliation" deals in certain rebel-held areas in a bid to stem the violence.

The renewed clashes came just days after the most recent round of UN-brokered peace talks in Geneva failed to produce concrete results. The United Nations has been trying to negotiate a ceasefire since 2012, but thus far nothing has stuck.

es/jm (AFP, dpa)