Al-Shallal, who until his defection was commander of the military police, said no chemical or nonconventional weapons are at the site.

NPR: Syria Threatens Retaliation For Israeli Airstrike

"The suicide bomber managed to enter and blow himself up in the middle of the mourners, " Shallal Abdul, mayor of Tuz Khurmato, told the AFP news agency.

BBC: Iraq bomb: Many dead in Shia mosque in Tuz Khurmato

Abdul-Aziz Jassem al-Shallal, who in December became one of the most senior Syrian army officers to defect, told The Associated Press by telephone from Turkey that the site they said was targeted is a "major and well-known" center to develop weapons known as the Scientific Research Center.

NPR: Syria Threatens Retaliation For Israeli Airstrike