DAMASCUS, July 22 (Xinhua) -- Intense clashes continued Sunday in a number of areas across Syria, particularly in the northern province of Aleppo, where armed opposition fighters said they have started an operation to liberate Aleppo from the government troops, activists say.
The clashes in Aleppo, Syria's second largest city and economic powerhouse of the country, have come against the backdrop of the clashes in Damascus that have been raging on since last Sunday.
Opposition fighters are seemingly trying to bring down and wobble the regime tight grip on the main cities of the unrest- ridden country.
In northern Aleppo, clashes have started Saturday in a number of areas, mainly the Salahuddien square. On Sunday, clashes also continued in more areas, according to activists.
A new rebels' brigade, al-Tawheed, apparently comprised of extremists, has declared the commencement of the operation to " free Aleppo," according to the Britain-based Syrian Observatory for Human Rights.
The observatory said violent clashes are taking place in the neighborhoods of Saif al-Dawla, al-Jameeliya and al-Meridian, adding that they are also taking place near the al-Zabadia police station and by the immigration and passport control buildings. Intense explosions were heard in the western part of the city, it said.
The state media said government troops clashed with armed men in different parts of Aleppo, killing many of them.
Aleppo has stayed relatively calm along with Damascus over the past 16 months of crisis elsewhere, that was met with resentment among the opposition factions.
The observatory also reported heavy bombardment and clashes in areas of central Homs province and eastern Deir al-Zour.
In the capital Damascus, meanwhile, intense fighting is currently taking place between the government troops and armed groups in al-Razi orchards area in the district of Mazzeh. Bursts of gunfire and shelling booms have been heard since Saturday night.
Pro-government media also reported the fighting in Mazzeh, saying that hefty losses have been inflicted to the armed groups.
The state news agency SANA said that several neighborhoods of the capital and in northern Idlib province have been declared rebel-free.
The recent intense clashes nationwide have cast dim prospect of any possible dialogue and peaceful solution. The rebels' leaders said they will not backdown in their fighting as the Syrian administration pledged it will hit back hard and cut the hand of anyone that dares to undermine the stability of the country.