DAMASCUS, Syria (AFP) — The Syrian army gave residents 48 hours to leave areas of the capital, where clashes are taking place between security forces and rebels pushing their "Damascus Volcano" offensive.

"These extremely violent clashes should continue in the next 48 hours to cleanse Damascus of terrorists by the time Ramadan begins" today, a security source told AFP, referring to the Muslim fasting month.

The Britain-based Syrian Observatory for Human Rights watchdog said that in the western district of Mazzeh alone, hundreds of people were on the move, "fearing a large-scale operation by regime troops."

Residents also fled the southern district of Tadamon and the Palestinian refugee camp Yarmuk, it said.

"The army stormed the Qaboon district with a large number of tanks," the Observatory's Rami Abdel Rahman told AFP.

The situation "is worse than catastrophic," one Damascus resident told AFP. "The medical and humanitarian situation is getting worse."

The authorities announced that state funerals will held today for the three regime officials killed in Wednesday's bombing.

"State funerals will be held in Damascus tomorrow, and then each of the bodies will be transported to his native town to be buried there," a security source told AFP.

Assad's brother-in-law and one of the Syrian security apparatus' hawks, Assef Shawkat, will be buried in the western province of Tartus.

Defence minister Daoud Rajha will be buried in his Christian town of Maalula near Damascus, and crisis cell chief Hassan Turkmani in northern Aleppo.

Assad's mother Anissa and his sister Bushra — Shawkat's widow — were in Tartus, on the Mediterranean coast, to receive condolences but it was unclear whether Assad himself would attend the funerals.

As deputy defence minister and a former military intelligence chief, Shawkat was hated by the anti-regime opposition.

He belonged to the Alawite community — a Shiite offshoot of Islam to which Assad's family also adheres.

The Observatory's Abdel Rahman said: "There is an escalation by the Syrian regime to avenge the operation that targeted the (security chiefs).

"The rebels have also escalated to reap the fruits of the attack, and to try to finish off the battle" for Damascus, he added.

A total of 107 were killed in violence yesterday — 47 soldiers, 42 civilians and 18 rebel fighters, according to the Observatory's figures.