Multiple bomb explosions on Wednesday hit a hilltop district in the Syrian capital Damascus populated by members of Syrian President Bashar al-Assad's Alawite sect, witnesses said Reuters reported.
The attack occurred a day after deadly tit-for-tat attacks in segregated neighbourhoods of the capital, deepening the sectarian divide between the Alawite sect, an offshoot of Shi'ite Islam that has ruled Syria since the 1960s, and Sunnis leading the 19-month revolt against the Assad family rule.
Smoke was seen rising from the Alawite enclave, known as Mezze 86, which is situated near the presidential palace, from what appeared to be heavy-calibre mortar bombs, several residents of Damascus said by phone.
"Ambulances are heading to the area and the shabbiha (pro-Assad militimen) are firing automatic rifles madly in the air," said a housewife who did not want to be further identified.
Syrian state television said the attack was carried out by mortar bombs, causing casualties, but gave no further details.
A car bomb exploded on Tuesday near a mosque in al-Qadam, a southern working-class Sunni neighbourhood of the capital, killing and wounding dozens, opposition activists said.
Al-Qadam, from where rebels operate, has been the target of heavy Syrian army artillery barrages in the last several weeks. Syrian warplanes have also hit the area.
Earlier, in Hai al-Wuroud, an Alawite neighbourhood on a hill on the northwest edge of the city, a bombing killed at least 10 people, according to state media.
Bomb attacks along sectarian lines have escalated lately in the 19-month-old uprising against Assad. Last month several bombs exploded during the Muslim Eid holiday near mosques in Sunni districts and the Damascus suburbs, killing and injuring dozens of people, activists said.