DAMASCUS, Sept. 28 (Xinhua) -- A pro-government radio said four Palestinian refugees were killed Friday when armed groups fired mortar shells at the al-Nairab camp in Syria's northern province of Aleppo.

Sham FM gave no further details, but also reported that loud explosion was heard Friday in the coastal city of Banyyas. It said, however, that the details surrounding the blast are still emerging.

The radio also said that a lieutenant-colonel was killed Friday when armed groups stormed a post at Mzaireeb area in southern Syria.

It added that the grand mufti of southern Daraa province was kidnapped by armed men on Friday.

Meanwhile, the state-TV said "terrorists" fire mortar shell at Sedi Miqdad area in the capital Damascus, destroying a mosque minaret.

The oppositional Local Coordination Committees, an activists' network, said the Syrian troops backed by a helicopter gunship shelled Friday the Damascus' suburb of Hameh, unleashed sweeping arrests at Jobar in the southern slice of Damascus.

It also reported heavy mortar shelling on the eastern Ghouta areas of Damascus. But the accounts could not be independently checked.

The reported violence in Damascus also coincided with intense fighting in Aleppo between the government troops and the armed rebels, who announced a day earlier the commencement of "decisive battle" in the northern province.