Gunmen thought to be army defectors killed at least eight Syrian troops Wednesday in a retaliatory attack after security forces killed a group of civilians.

The British-based Syrian Observatory for Human Rights said the defectors ambushed a military convoy traveling through the village of al-Asharna, near Hama.

Hours earlier, rights activists said Syrian security forces opened fire on a car traveling through a nearby village , killing five civilians.

The latest shootings come a day after a surge in deadly violence in Syria.

The Syrian Observatory for Human Rights said loyalist forces killed at least 24 people Tuesday, most in Idlib province, where an army raid killed 11 civilians.

The group says Syrian army defectors later killed seven government security force members on Tuesday when they ambushing a patrol.

Up to eight more civilians were killed Tuesday in a separate incident in Idlib when Syrian troops fired on crowds attending funeral processions for those killed earlier.

The United Nations human rights office says it has received credible reports from a variety of sources showing the Syrian death toll at more than 5,000 since March, when the unrest first began. Syria's U.N. ambassador has rejected the figure as “incredible.”

Syria's uprising has turned increasingly violent in recent months, with defecting soldiers fighting back against the army and once-peaceful protesters taking up arms to protect themselves.

A general strike continued for a third day Tuesday in several regions across Syria as activists push for an end to President Bashar al-Assad's rule through a campaign of civil disobedience.