A total of 55,219 people were killed in the Syrian civil war in 2015, said the Britain-based Syrian Observatory for Human Rights, which relies on a network of activists and other sources inside Syria.
The Observatory said some 20,000 of those were civilians, including 2,574 children, while 7,728 were rebel combatants and some 16,000 were government troops and allied militiamen.
Lebanon’s Shiite movement Hezbollah lost 378 fighters in Syria in 2015, it added.
Syria’s conflict began with largely peaceful protests in 2011 against the rule of President Bashar Assad, which quickly escalated into civil war following a harsh crackdown on dissent. The conflict has killed more than 250,000 people and generated a massive refugee crisis.