A total of 235 activists were killed Sunday in fighting between the Syrian government troops and rebels in the northern city of Aleppo, according to the website of a pro-government al-Watan newspaper.

These rebels reportedly died in the new round of battle in Aleppo, the main battleground since July.

Al-Watan also said that more than 500 shops in an ancient marketplace that could be dated back to 312 B.C. had been destroyed by the flames caused by heavy gunfire this weekend.

On Saturday, a fire sparked by battles tore through the market, one of the best-preserved bazaars in the Middle East. It was the worst blow yet to the city's historic center and to a UNESCO World Heritage site in Syria.

Aleppo has been gripped by fighting on an unprecedented scale since Thursday and the London-based Syrian Observatory for Human Rights said that rebel mortar fire damaged two helicopters at the area's al-Nairab military airport.

The army, for its part, shelled several districts of Aleppo and battled rebels in Aleppo's northern district of Jandul, the Observatory said.