BEIRUT: Syrian rebels battled government troops near a landmark 12th century mosque in the northern city of Aleppo Tuesday, while fierce clashes raged around a police academy west of the city, activists said.

The fighting near the Umayyad Mosque in the walled Old City threatened to further damage the historic structure, part of which was burned during clashes last year.

Since July 2012, government forces and rebels seeking to topple President Bashar Assad have been battling over Aleppo, the country’s largest city and a major prize in the civil war. While rebels have gradually expanded the amount of turf under their control, seven months of street fighting, airstrikes and shelling have left much of the city, considered one of Syria’s most beautiful, in ruins.

The opposition Syrian Observatory for Human Rights reported intense clashes with heavy gunfire and explosions near the mosque.

Syria’s state news agency said “terrorists” had detonated explosives near the building’s south wall, causing “material damages.” Assad’s regime refers to the opposition as “terrorists.”

The mosque, also known as the Great Mosque of Aleppo, sits near a medieval covered market in the Old City, which is a UNESCO World Heritage site. The mosque was heavily damaged in October 2012, just weeks after a fire gutted the market.

Syria’s nearly 2-year-old civil war has left its mark on other gems of the country’s rich archaeological and cultural heritage.

At least five of Syria’s six World Heritage sites have been damaged in the fighting, according to UNESCO, the U.N.’s cultural agency. Looters have broken into one of the world’s best-preserved Crusader castles, Crac des Chevaliers, and ruins in the ancient city of Palmyra have been damaged.

Both rebels and regime forces have turned some of Syria’s significant historic sites into bases, including citadels and Turkish bath houses, while thieves have stolen artifacts from archaeological excavations and museums.

To the west of Aleppo, activists reported fresh fighting Tuesday near the police academy that has become a key government military installation.

The Britain-based Observatory said the two sides were shelling each other’s positions while the government launched airstrikes in the area.

Video posted online in recent days shows rebel groups firing homemade rockets and mortars at the academy and blasting it with captured tanks. The videos appeared genuine and corresponded with other AP reporting.

The Observatory said the dead in the last two days of fighting in the area included 26 rebel fighters, 40 soldiers and five pro-government militiamen.

The police academy, which activists say the government has turned into a military base, has recently emerged as a new front in the battle for Aleppo. Losing the facility would hinder the regime’s ability to shell opposition areas and support its troops inside the city.

An Aleppo activist who goes by the name Abu al-Hasan said via Skype that rebels coming from Idlib province to the west are now trying to clear the army from residential areas near the academy before they attack it.

“Yesterday and today they have been trying to go forward but there are lots of shelling and airstrikes,” he said.

The fighting has largely destroyed Aleppo and caused humanitarian conditions for the city’s remaining civilians to plummet.

Airstrikes were also reported in the southern province of Deraa, the eastern outskirts of Damascus, the northwestern province of Idlib, the northern province of Raqqa and the eastern city of Deir al-Zor.

An AFP correspondent in Deir al-Zor said two MiGs flew repeated low-level sorties over the Sheikh Yassine neighborhood for more than three hours during the morning, dropping at least 50 bombs on rebel positions.

The strikes were accompanied by shelling from artillery, as troops tried to open a breach in rebel defenses.

“They have been preparing an offensive for a week and have been moving troops in the center of the neighborhood,” local rebel commander Khaled bin al-Walid said.

In Damascus, three young children were killed by army shelling on the eastern district of Jobar, the Observatory said.

The Observatory also said the death toll in a car bomb attack in Damascus had risen to eight. All were regime security officers, it said.

The blast late Monday struck a security checkpoint in the neighborhood of Qaboun, less than a kilometer from Abbasid Square, northeast of downtown. It was followed by smaller blasts thought to be mortar shells landing in various districts of the capital.

The explosions and subsequent gunfire caused panic among residents who hid in their apartments.

Syria’s state news agency said the blast was caused by a suicide car bomber and caused an unspecified number of casualties.