BEIRUT — Dozens of soldiers and security forces were gunned down by suspected army defectors in southern Syria, activists said today.

Monday’s hours-long clash in the southern province of Daraa came on a particularly bloody day in Syria, with as many as 90 people killed across the country. The brazen attack by the army defectors suggested a new confidence among troops who have sided with the protesters.

The ambush that comes as President Bashar Assad increasingly appears unable to manage the crisis.

The U.N. estimates the regime’s military crackdown on an 8-month-old uprising has killed 3,500 people in the past eight months. November is shaping up to be the bloodiest month of the revolt, with many more than 300 people killed so far.

The latest death toll was compiled by sources including British-based Syrian Observatory for Human Rights, the Local Coordination Committees activist coalition and morgue officials.

Rami Abdul-Rahman, head of the observatory, confirmed that 34 soldiers were killed in an ambush in Daraa.