The international chemical weapons watchdog said Tuesday that it plans to send a fact-finding mission to Syria to investigate allegations that the government used chlorine gas in attacks against civilians in recent weeks.

The announcement came as mortar fire and a bombing killed more than 50 people in government-controlled parts of Damascus and Homs, underscoring the risk that a prolonged insurgency will continue to bleed areas where rebels are being quashed.

In a statement issued at its headquarters in The Hague, the Organization for the Prohibition of Chemical Weapons (OPCW) said inspectors would leave “soon” to verify whether chlorine gas was used in bombs dropped on at least two villages in rebel-held areas of northern Syria.

President Bashar al-Assad’s government has agreed to the mission and has promised to provide security in territory under its control, the statement added. But it is not clear how the inspectors will cross dangerous front lines to reach the opposition areas where the attacks occurred.

Although the attacks have not been independently verified, videos posted on YouTube showed scores of civilians gasping for breath in hospitals after reportedly inhaling gases unleashed by bombs dropped from planes. The number of deaths has been relatively low, however, compared with the hundreds who died in August’s sarin gas attacks in the suburbs of Damascus, which triggered threats of U.S. airstrikes.

According to the Violations Documentation Centre, these videos come from media activist Abu Mahdi al-Hamwi, who was in Kaft Zeita in Syria on April 11.

The first video reportedly shows an explosive barrel dropping on the city.

Two more reportedly show victims in the hospital there.

Syria is in the process of dismantling its chemical weapons arsenal under the terms of a U.S.-Russian deal negotiated to avert the strikes. The task is set for completion by June 30, and the OPCW said Sunday that 92.5 percent of the arsenal had been destroyed or shipped out of the country, making the deadline feasible.

But chlorine is not covered by the Chemical Weapons Convention, which Syria agreed to sign, so the government is not obliged to reveal its stores of the substance. Syria has denied using chlorine in bombs.

It is highly unlikely that a discovery by the inspectors that chlorine has been used in bomb attacks would trigger any meaningful response, said Firas Abi Ali of the London-based IHS Country Risk consultancy. “If confirmed, it indicates that Assad assesses he can use these weapons with impunity given U.S. unwillingness to intervene directly,” he said.

Meanwhile, violence continued throughout the country, with some of the deadliest attacks occurring in areas where the government has been consolidating its control.

A car bomb in the central city of Homs killed 36 people and injured more than 40, according to the official Syrian Arab News Agency (SANA). The attack targeted the mainly Alawite Zahra neighborhood, where residents mostly
support Assad, a member of the Shiite Alawite sect. It occurred at a time when the government is looking to squeeze the last few pockets of resistance left in the once-rebellious city.

In Damascus, mortar shells struck a renowned Islamic school in the Old City, killing 17, according to SANA. Mortar attacks elsewhere in Damascus province killed at least four people.

The violence comes as Syria prepares to hold a presidential election on June 3 that Assad is certain to win because the laws are not structured to permit real competition. Eleven candidates, including Assad, have filed to run, SANA reported.

Ahmed Ramadan contributed to this report.