DAMASCUS, Syria -- The Syrian president vowed on Friday to rid the country of Muslim extremists whom he blamed for a suicide blast the previous evening that killed dozens of people, including a top Sunni preacher who was a staunch supporter of Bashar Assad.
And in a warning to rebels battling to topple his regime, the Syrian leader pledged that his troops will "wipe out" and clean the country of the "forces of darkness."
Assad's statement came as the Syrian Health Ministry raised the death toll from the Thursday night bombing in Damascus to 49, after seven of the wounded died overnight in hospital.
In the attack, a suicide bomber blew himself up inside a mosque in the heart of the Syrian capital, killing Sheikh Mohammad Said Ramadan al-Buti as he was giving a sermon. The blast also wounded 84 people.
It was one of the most stunning assassinations of the two-year civil war and marked a new low in the conflict: while suicide bombings blamed on Islamic extremists fighting with the rebels have become common, the latest attack was the first time a suicide bomber detonated his explosives inside a mosque. The grandson of the 84-year-old al-Buti was among those killed in the attack.
In the statement carried by Syria's state SUNA news agency, Assad said al-Buti represented true Islam in facing "the forces of darkness and extremist" ideology.
"Your blood and your grandson's, as well as that of all the nation's martyrs will not go in vain because we will continue to follow your thinking to wipe out their darkness and clear our country of them," said Assad.
Syria's crisis started in March 2011 as peaceful protests against Assad's authoritarian rule. The revolt turned into a civil war as some opposition supporters took up arms the fight a harsh government crackdown on dissent. The U.N. says more than 70,000 people have been killed since.
It was not immediately clear when al-Buti's funeral would take place. The government declared Saturday as a day of mourning and state-run Syrian TV halted its regular programs on Friday to air readings from the Muslim holy book, the Quran, as well as speeches of the late cleric.
Al-Buti was the most senior religious figure to be killed in Syria's civil war and his slaying was a major blow to Assad. The preacher had been a vocal supporter of the regime since the early days of Assad's father and predecessor, the late President Hafez Assad, providing a Sunni cover and legitimacy to their rule. Sunnis are the majority sect in Syria while Assad is from the minority Alawite sect -- an offshoot of Shiite Islam.
In a speech earlier this month, al-Buti had said it was "a religious duty to protect the values, the land and the nation" of Syria. "There is no difference between the army and the rest of the nation," he said at the time -- a clear endorsement of Assad's forces in their effort to crush the rebels.
The mosque bombing was also among the most serious security breaches in Damascus. In July, an attack that targeted a high-level government crisis meeting killed four top regime officials, including Assad's brother-in-law and the defense minister.
Last month, a car bomb that struck in the same area, which houses the headquarters of Syria's ruling Baath party, killed at least 53 people and wounded more than 200.