DAMASCUS, Syria — The Syrian government released Saturday hundreds of detainees including some who backed the insurgency against President Bashar Assad on the eve of a major Muslim holiday. Hours after the release, a car bomb exploded in a rebel-held northern town near the border with Turkey killing and wounding dozens of people, according to the opposition Civil Defense in Idlib and the Britain-based opposition monitoring group the Syrian Observatory for Human Rights. The explosion at a market in Dana, killed at least 10 people, including children, and wounded 30, according to the Observatory.