The BBC reports allegations that Syrian rebels have used sarin gas, a nerve agent that causes asphyxiation and is classified as a weapon of mass destruction and banned under international law.

Amid reports that the Syrian military is secretly stockpiling chemical weapons, U.N. human rights investigators allegedly have testimony indicating Syrian rebels have used sarin gas. Interviews with victims and doctors have provided “strong, concrete suspicions” that rebels used the deadly nerve agent, according to a lead investigator, though the U.N. does not have “incontrovertible proof.” There’s no evidence yet that the Syrian military used sarin. The latest Geneva-based investigation is separate from U.N. Secretary-General Ban Ki-moon’s currently stalled inquiry into the use of chemical weapons in Syria.

Reuters:

U.N. human rights investigators have gathered testimony from casualties of Syria's civil war and medical staff indicating that rebel forces have used the nerve agent sarin, one of the lead investigators said on Sunday. The United Nations independent commission of inquiry on Syria has not yet seen evidence of government forces having used chemical weapons, which are banned under international law, said commission member Carla Del Ponte. "Our investigators have been in neighboring countries interviewing victims, doctors and field hospitals and, according to their report of last week which I have seen, there are strong, concrete suspicions but not yet incontrovertible proof of the use of sarin gas, from the way the victims were treated," Del Ponte said in an interview with Swiss-Italian television. "This was use on the part of the opposition, the rebels, not by the government authorities," she added, speaking in Italian. Del Ponte, a former Swiss attorney-general who also served as prosecutor of the International Criminal Tribunal for the former Yugoslavia, gave no details as to when or where sarin may have been used.

Israeli warplanes have targeted Syria twice in the last three days, and now Israel is deploying two batteries of its Iron Dome rocket defense system to the north of the country. The second airstrike early Sunday, hit a military facility just north of the capital, a Western intelligence expert confirmed. Israel declined to comment. “The sky was red all night,” said one man who lives less than a mile from the facility. “We didn’t sleep a single second. The explosions started after midnight and continued throughout the night.” The facility reportedly held Iranian-supplied missiles, which Israel contends were headed for Lebanon’s Hezbollah. Israel attacked the same site three months ago. President Obama, meanwhile, defended Israel on Sunday.