Syrian President Bashar Assad’s regime used chemical weapons in two attacks in Damascus 10 days ago, a senior Israeli defense official said Monday.

The official said that nonlethal agents were used to incapacitate opposition fighters.

He claimed that two attacks were carried out on March 27 in the Harasta neighborhood of Damascus, and that the effects of the chemicals lasted for several hours.

According to the official, the compound used in the attacks was not listed among the chemicals that Syria committed to dispose of when it signed an agreement in September 2013 to give up its chemical weapons.

The assertion backs reports from opposition groups, which last month claimed that Assad loyalists had used chemical agents in attacks.

Israeli Defense Minister Moshe Ya’alon said on Monday that 60 percent of Syria’s chemical weapons have been removed from the country in recent months in accordance with the agreement.

Ya’alon added that Israel was keeping a close eye on the removal process, specifically in order to ensure that none of the chemical agents were transferred to the Hezbollah terror group.

Israeli intelligence exposed the Assad regime’s use of chemical weapons last year. The Israeli army’s military intelligence analyst Itai Brun, in April 2013, delivered a bombshell lecture in which he declared publicly that Assad was using nerve gas against rebel forces: “To the best of our professional understanding, the regime has used lethal chemical weapons,” he said at the time, and specified that the IDF believed the toxic element was sarin. He noted then that it had been used on more than one occasion, including in an attack on March 19, 2013.

His assertion was initially queried, but subsequently accepted, by US and other officials. The Israeli conclusion was “based on very special work,” by a team that “saw very clearly,” Brun later said.

The international community, shocked by a chemical attack by Assad’s forces in August 2013 that killed hundreds near Damascus, aims to remove and destroy 1,300 metric tons of chemicals by June 30.

The Associated Press contributed to this report.