BEIRUT -- More than 50 people were killed and scores injured Tuesday in Syria during a series of mortar and car bomb attacks targeting pro-government districts in Damascus and Homs, according to official and activist accounts.
The deadliest strike was a car bombing near a busy intersection in war-ravaged Homs that left at least 36 dead and 85 injured, Syria's official news agency reported. Some reports indicated that two car bombs had been detonated within 300 yards of each other, and that the death toll had reached as high as 65.
In the vicinity of Damascus, authorities reported that mortar barrages struck a school and a center for displaced people, killing at least 18. Tuesday's strikes were among the deadliest mortar attacks reported in the capital, where rebels based in the outskirts frequently shell civilian neighborhoods.
Tuesday's onslaught marked the latest in stepped-up attacks on civilian targets in both cities.
The official media blamed all of Tuesday's attacks on "terrorists," its standard term for rebels fighting to overthrow the government. The blasts came a day after President Bashar Assad announced that he would seek a third seven-year term in the June 3 election. Opposition activists have dismissed the election as a farce. But there was no known direct link between the attacks and the announcement of Mr. Assad's candidacy.
Homs has long been a key battleground in the Syrian conflict, now in its fourth year.
This month, 25 people were killed in a pair of car bomb strikes that, like Tuesday's attack, struck a neighborhood that is home to many in the minority Alawite Muslim sect, a Shiite offshoot whose members include Mr. Assad and high-ranking commanders of the Syrian security services. Homs' volatile sectarian mix -- along with Alawites, it is home to a significant Christian minority, along with a Sunni Muslim majority -- has been a factor in the violence there. Most rebels come from the country's Sunni majority, while Alawites and Christians generally support the government.
In recent months, Syrian forces have recaptured much of Homs from rebels and cornered remaining opposition fighters in a few enclaves, including the heart of the Old City. The government says hundreds of rebels have surrendered, and that negotiations are continuing in a bid to persuade remaining fighters there and elsewhere to lay down their arms or evacuate the city.
Also Tuesday, the Hague-based Organization for the Prohibition of Chemical Weapons said it would send a team to Syria to investigate opposition allegations that government forces have used toxic chlorine gas. The government has denied the charges.
Under a United Nations-backed program, Syria has shipped 92.5 percent of its chemical weapons material out of the country for destruction, international monitors confirm. Syria has also closed chemical weapons storage and production sites, and has destroyed buildings, equipment and containers under the program, monitors say.
Syrian officials say rebel attacks on chemical weapons removal convoys and related operations slowed the disarmament effort, causing several deadlines to be missed.
An exile-based dissident group, the Syrian National Coalition, on Tuesday called upon the international monitoring team to also investigate "Assad's hidden chemical weapons stockpile." The government says it has declared its entire chemical inventory and denies having secret stockpiles.