BEIRUT A loud explosion was heard near a military site in the Syrian port city of Latakia on Wednesday, opposition groups and state media said, but the cause of the blast was unclear.
Explosions in Latakia, part of President Bashar al-Assad's stronghold on the Mediterranean coast, have been rare during Syria's two-year-old conflict.
State television said the blast was caused by a technical fault at a weapons store at a military engineering base, and said six people were hurt wounded.
The pro-opposition Syrian Observatory for Human Rights said the blast on the base, on the southern outskirts of Latakia, was still unclear but said 13 soldiers were, some of whom were in critical condition.
Residents said on social media the blast shook much of the city and shattered windows.
The Syrian war has divided much of the country into territories held by Assad's forces or the rebels.
Assad has a strong hold on the coastal region and the capital. The coast is home to a large portion of the minority Alawite community, to which Assad himself belongs, and which has largely stood behind the president.
Latakia is also home to a large number of Sunni Muslims, Syria's majority population which has mostly backed the revolt.
Its location in the Alawite enclave has meant that the area is heavily guarded. Rebels have repeatedly launched operations in the Latakia countryside but the city has remained largely untouched.