Syria's umbrella opposition National Coalition on Tuesday condemned a powerful bomb blast in central Damascus that killed at least 15 people, and said the regime bore responsibility for the attack.
"The Syrian Coalition, on behalf of the Syrian people, condemns without any hesitation all bombings and hostilities against civilians, and considers these acts crimes against humanity," the group said in a statement.
"Those responsible must be brought to justice," the group added, laying responsibility for the blast on the regime of President Bashar al-Assad.
"The Syrian Coalition holds the Assad regime responsible for these crimes, especially considering that they had previously placed intense security in the area where the bombings took place and in the surrounding neighborhoods."
The bomb attack on Monday took place near the Sabaa Bahrat Square, close to Syria's central bank, killing 15 people and injuring more than 100. No group has claimed responsibility for the explosion, which caused extensive damage.
The National Coalition said the blast was "part of a long list of recurring crimes in which the Assad regime targets mosques, churches, bakeries, homes, shelters and schools with heavy and chemical weaponry."
The statement gave no evidence for the claim that the regime was behind the blast, which came after a suicide bomber blew himself up in a Damascus mosque on March 21, killing at least 49 people, including a pro-regime Sunni cleric.
As the uprising against Assad's regime has evolved from peaceful anti-regime protests to civil conflict, bombings have become a regular feature of the fighting.