Human Rights Watch says Syria is carrying out "unlawful" deliberate and indiscriminate attacks against civilians, and is urging the international community to pressure the government to stop.
The group released a report Thursday describing 59 air strikes in opposition areas of Aleppo, Idlib and Latakia between August and December last year. Human Rights Watch says those attacks - some hitting bakeries and hospitals - killed 152 civilians, and appear to be part of a systematic campaign that amounts to crimes against humanity.
The report says the air strikes included the use of unguided bombs, fighter jets and high-flying helicopters without the ability to tell the difference between civilians and combatants on the ground.
Additionally, Human Rights Watch says four Syrian Air Force defectors told the group that they lacked the technology to "identify and target specific military objectives in urban areas."
In 41 of the 59 attacks in the report, the group says it identified possible opposition targets, including Free Syrian Army bases, within 50 to 400 meters of air strikes that it presumes missed those targets.
Human Rights Watch wants opposition fighters to take steps to protect civilians, including avoiding deploying their forces near densely populated areas when possible.
The group is also urging governments and companies to stop selling and sending weapons and ammunition to Syria.
The report cites figures from the Violations Documentation Center and the opposition Local Coordination Committees saying government air strikes killed 4,472 people, mostly civilians, between July 2012 and late last month.