Two car bombs exploded in a Syrian military compound in Palmyra on Wednesday, killing dozens, according to Reuters, citing local opposition campaigners.
Syrian activists claimed the blast killed "no less than 12 members of the Syrian security services, with more than 20 others injured."
The Britain-based Syrian Observatory For Human Rights said the car bombs targeted "the military intelligence (al-Badiya) and general intelligence (state security) branches in the city of Tadmur (Palmyra)."
The Syrian Arab News Agency (SANA), Syria's state news agency, reported "terrorists" had exploded the cars in a residential area, killing several "citizens."
The Syrian Observatory said "8 civilians were injured, some severely," by heavy gunfire that came after the explosions.
Islamic militants fighting for the downfall of President Bashar al Assad's regime often use car bombs to hit state institutions, according to the Associated Press.
News of the bombing follows a UN announcement on Wednesday that warned by June the number of refugees fleeing Syria could reach 1.1 million.
Antonio Guterres, the UN High Commissioner for Refugees, said Syria's situation is "the most dramatic crisis we are facing today."
So far about 60,000 people have died in Syria's civil war between Bashar's government and the factions of the rebel Free Syrian army, according to the Boston Globe.