Damascus (AFP) - Syria’s new authorities launched a sweeping security operation Friday after clashes with fighters loyal to former president Bashar al-Assad, the biggest challenge to their rule so far, left at least 71 people dead.

The violence saw the fiercest attacks on the country’s authorities since Assad was ousted in December in a lightning offensive by Islamist-led rebels.

Restoring security has been one of the most complex tasks for the new authorities since Assad’s fall, which ended over 13 years of civil war triggered by his crackdown on pro-democracy protests.

A curfew was imposed in the coastal province of Latakia, the Assad clan’s former stronghold and home to a sizeable Alawite community, the same religious minority as the former president.

Security forces began what official news agency SANA described as a “large-scale” operation in cities, towns and the mountains of Latakia and neighbouring Tartus, following the arrival of reinforcements.

The operation “targeted remnants of Assad’s militias and those who supported them”, a security official cited by SANA said, as he called on civilians to “stay in their homes”.

The defence ministry said it had sent reinforcements to the cities of Latakia and Tartus.

According to the Syrian Observatory for Human Rights’ latest toll, the clashes killed 71 people over the past day, among them 35 members of the security forces, 32 gunmen and four civilians.

The Observatory, a Britain-based monitor, also reported dozens of people wounded and others taken prisoner by both sides.

The authorities also imposed curfews in Homs and Tartus.

Mustafa Kneifati, a security official in Latakia, said that in “a well-planned and premeditated attack, several groups of Assad militia remnants attacked our positions and checkpoints, targeting many of our patrols in the Jableh area.”

Kneifati said security forces would “work to eliminate their presence”.

“We will restore stability to the region and protect the property of our people,” he said.

SANA said meanwhile that security forces had detained Ibrahim Huweija, a general who was “accused of hundreds of assassinations” under the rule of Assad’s father and predecessor, Hafez al-Assad.

- ‘Everyone’s afraid’ -

Ali, a farmer living in Jableh, told AFP he saw “urban battles and street fighting”.

“All night, we heard the sounds of gunfire and explosions,” he added.

“Everyone’s afraid… we are trapped at home and we can’t go out.”

Thursday’s clashes saw security forces conduct helicopter strikes after they clashed with gunmen loyal to Assad-era special forces commander Suhail al-Hassan in the village of Beit Ana, also in Latakia.

Tensions had erupted after residents of Beit Ana, the birthplace of Suhail al-Hassan, prevented security forces from arresting a person wanted for trading arms, the Observatory said.

Security forces subsequently launched a campaign in the area, resulting in clashes with gunmen, it added.

The killing of at least four civilians during a security operation in Latakia also sparked tensions, the monitor said on Wednesday.

Security forces launched the campaign in the Daatour neighbourhood of the city on Tuesday after an ambush by “members of the remnants of Assad militias” killed two security personnel, state media reported.

Islamist rebels led by Hayat Tahrir al-Sham launched an offensive that toppled Assad on December 8, when he fled the country to Russia with his family.

Multiple high-ranking Assad loyalists have also fled since the former president’s ouster, but many others remain in the country.

Syria’s new security forces have since carried out extensive campaigns seeking to root out Assad loyalists from his former bastions.

Residents and organisations have reported violations during those campaigns, including the seizing of homes, field executions and kidnappings.

Syria’s new authorities have described the violations as “isolated incidents” and vowed to pursue those responsible.

Ahmed al-Sharaa, whose Islamist rebel group led the offensive that ousted Assad, has since become interim president and engaged in high-level contacts with governments around the world.

Saudi Arabia, which Sharaa has visited in February, reaffirmed its support Friday for the new authorities, branding as “crimes” by “outlaw groups” the attacks on security forces.