UN Secretary-General Ban Ki-moon has said he believes Al-Qaeda is behind two suicide car bombings that killed 55 people and wounded some 370 others in Damascus on May 10.
Ban said Al-Qaeda's involvement in the region "has created very serious problems."
Syrian authorities have said terrorists were behind the violence that has engulfed the country for more than a year now.
The Syrian government sent the names of 26 foreign nationals it has apprehended since fighting started in the country, saying 20 of them were members of Al-Qaeda who crossed into Syria from Turkey.
Based on reporting by Reuters and AP