At least 25 people, many of them children, have been killed in two Syrian government air strikes, activists say.
The UK-based Syrian Observatory For Human Rights (SOHR) said one strike hit a rebellious Damascus suburb, killing at least nine children.
It said a second targeted rebel-held areas in the Kurdish-majority Hasaka province, killing at least 16 people.
Human rights groups accuse the Syrian government of targeting civilians.
The air strike in Damascus hit the suburb of Qaboun, which has been a frequent battle ground between the Syrian military, loyal to President Bashar al-Assad, and rebel forces intent on overthrowing him.
The strikes in Hasaka province targeted rebel-held areas around the village of Haddad.
'Black smoke rising'
Three woman and two children were among the dead, the SOHR said.
Rami Abdel Rahman, its director, told the Agence France-Presse news agency that a group of rebels used an area near the site of Sunday's air strike as a gathering place, but that a group of houses some distance away had been hit.
SOHR monitors human rights violations on both sides of the conflict via a network of contacts across Syria.
An activist in the area, who gave his name only as Abu Qasem, told Associated Press news agency by telephone that there were "plumes of black smoke rising over the town, with continuous army fire from ground and air attacks".
The SOHR estimates that March was the bloodiest month yet, with more than 6,000 people killed - a third of them civilians.
The UN estimates that some 70,000 people have died in the country's two-year conflict.
Last week a report by US-based Human Rights Watch condemned the Syrian government for employing what it said were indiscriminate and sometimes deliberate airstrikes against civilians.
The latest deaths came a day after the observatory said at least 18 people were killed in an air-strike in the town of Saraqeb in the north-western province of Idlib.
Separately, the state Sana news agency said three journalists working for state TV in Aleppo province were wounded in a car bombing on Sunday.
It is not clear who carried out that bombing. The Assad government is being fought by a range of groups.
Last week one of the most influential, Islamist group Jabhat al-Nusra, announced its alignment with al-Qaeda.
The Syrian opposition's main political grouping, the Syrian National Coalition, released a statement on Sunday expressing its concern at the move.
The announcement "contradicts the will of the Syrian people and the objectives of the revolution", it said.