BEIRUT — The Syrian army recaptured the northern rebel stronghold of Idlib near the Turkish border, a major base that military defectors held for months, a pro-government newspaper and an activist group said Tuesday.
The three-day operation to capture Idlib gives the regime some momentum, as it tries to crush the armed resistance. It also feeds international condemnation.
The Arab League chief said the regime's killing of civilians amounts to crimes against humanity, and he called for an international inquiry.
New York-based Human Rights Watch said troops have planted land mines near Syria's borders with Turkey and Lebanon, along routes used by people fleeing the violence and trying to reach safety in neighboring countries.
Human Rights Watch said its report is based on accounts from witnesses and Syrian mine removers and that the land mines have already caused civilian casualties.
Fresh from a monthlong campaign that drove rebels out of another key base in central Homs, President Bashar Assad's forces launched a siege on the city of Idlib three days ago. The city largely had been under control of hundreds of fighters for the rebel Free Syrian Army.
The Al-Watan daily and the Britain-based Syrian Observatory for Human Rights said government troops were in control of Idlib on Tuesday.
Idlib, a predominantly Sunni city of some 150,000 people located about 100 miles north of Homs, was among the first to fall in the hands of army defectors last summer.
Many feared the offensive in Idlib could end up like the regime's campaign against the rebel-held neighborhood of Baba Amr in the city of Homs. Troops besieged and shelled Baba Amr for almost a month before capturing it on March 1, after hundreds of civilians were killed.
Arab League chief Nabil Elaraby said those responsible for the killings must be brought to trial.
"There must be an impartial international inquiry into what is happening to uncover those responsible for these crimes to face justice," he said in Cairo.
Mr. Assad has made a series of gestures toward reform to try to allay the crisis, but his opponents say his efforts are too little, too late. On Tuesday, he set nationwide parliamentary elections for May 7.
The vote was initially to take place in March but was postponed after last month's referendum on the country's new constitution that allowed new political parties to run.
In the past, the National Progressive Front, which includes Mr. Assad's ruling Baath party, dominated elections and the 250-member legislature.
In northern Syria, the Observatory and another activist group, the Local Coordination Committees, reported intense clashes between government troops and rebels in the town of Maaret al-Numan, in Idlib province, on Sunday night.
The Local Coordination Committees said four civilians were killed in the government shelling, while the Observatory said 10 soldiers were killed when their checkpoint was attacked by defectors.
Earlier this year, Mr. Assad's forces began major military operations to retake rebel-held areas, starting with an attack that recaptured several suburbs of the capital, Damascus, and followed by the offensive in Homs.
The U.N. refugee agency said 230,000 Syrians have fled their homes since the uprising against Mr. Assad's regime began last year. The United Nations says more than 7,500 people have been killed in the past 12 months.