Rebel forces and Syrian army units waged deadly clashes around elite Republican Guard posts in the suburbs of Damascus on Tuesday, as 31 people were killed across the country, a monitoring group said.
"Violent clashes are taking place around positions of the Republican Guard in Qudsaya and Al-Hama," eight kilometres (five miles) from central Damascus, Syrian Observatory for Human Rights head Rami Abdel Rahman told AFP.
Six people were killed in Qudsaya, according to the Observatory, without specifying if they were civilians or fighters.
Fighting has intensified in recent weeks in and around the capital, where government buildings and security posts are heavily defended, but the violence on Tuesday was the most intense in the area, Abdel Rahman said.
"This is the first time that the regime uses artillery in fighting so close to the capital," he said. "This development is important because it's the heaviest fighting in the area and close to the heart of the capital."
"These suburbs are home to barracks of troops which are very important for the regime like the Republican Guard. This is also where families of (army) officers live," he said.
The rebels blew up an artillery piece at the entrance to Qudsaya, according to Abdel Rahman.
The Observatory also reported that troops backed by "large military vehicles," stormed the Barzeh neighbourhood of the capital amid heavy shooting.
Elsewhere, five people, including a child, were killed in the eastern city of Deir Ezzor, where several neighbourhoods came under army bombardment.
In the town of Khan Sheikhun in the northwest province of Idlib, at least four members of the security forces were killed in a car bombing.
Also in Khan Sheikhun, one rebel fighter was killed in clashes with regime troops and one woman was killed during shelling.
Elsewhere in the province, five regime troops were killed in Khan Sabel, while two civilians were killed in the town of Saraqeb, which was hit by "more than 20 shells in half an hour" after midnight, according to the watchdog.
It added that a helicopter was reportedly shot down during the clashes.
In central Hama province, a rebel battalion commander was killed in the town of Suran during clashes, which took place after midnight Monday between rebels and regime troops.
Six people were killed in the southern province of Daraa, known as the cradle of the uprising, including three who died during shelling on the town of Kafr al-Shams, which saw clashes as regime troops tried to gain control over the area. The other three were killed in shelling on the town of Atman.
On Monday, 95 people were killed, including 61 civilians, as the army pounded rebel strongholds and other towns and cities.
According to the Britain-based Observatory, the government's suppression of an anti-regime revolt in Syria since March 2011 has cost more than 15,000 lives.