Updated

GUVECCI, Turkey -- Syrian security forces made sweeping arrests Thursday, randomly detaining males above the age of 16 in a northwestern province that has been under military siege for a week, a Syrian human rights activist said.

Mustafa Osso said the arrests were mainly concentrated in the Jisr al-Shughour area, the town of Maaret al-Numan and nearby villages, where the army has been massing troops for days in what appears to be a preparation for a fresh military operation.

Osso added that troops opened fire early Thursday in the outskirts of Maaret al-Numan, a town of 100,000 on the highway linking Damascus with Syria's second-largest city, Aleppo. No casualties were reported.

The Syrian Observatory for Human Rights said dozens of tanks, armored personnel carriers and buses used to transport anti-terrorism forces were deploying around the town of Khan Sheikhon south of Maaret al-Numan. It added that residents were fleeing the town that is surrounded from three sides.

Syrian President Bashar Assad has unleashed the military to crush a popular uprising against his authoritarian rule. Human rights activists say more than 1,400 Syrians have been killed since the uprising began in mid-March.

Osso said the number of people detained daily in the area is at least 300.

Also Thursday, Syria's state-run news agency said Assad expressed confidence that "Syrians will get out of this crisis stronger and more coherent."

The Syrian government blames a foreign conspiracy for the unrest, saying religious extremists -- not true reform-seekers -- are behind it. The government also has denied there are any cracks in the military amid rumors that Sunni army conscripts are refusing to fire on civilians.

The rumors illuminate Syria's potentially explosive sectarian tensions. The Assad regime is dominated by the Alawite minority, an offshoot of Shiite Islam, but the country is overwhelmingly Sunni.

The sect's longtime dominance has bred resentments, which Assad has worked to tamp down by pushing a strictly secular identity in Syria. But Assad is now relying heavily on his Alawite power base to crush the resistance.

Late Wednesday, a lieutenant colonel and four privates deserted the Syrian army and fled to Turkey, Turkey's state-run Anatolia news agency reported. They would be joining a number of civil servants as well as other soldiers and police officers who are already sheltering in the refugee camps, it said.

The tension in the northwestern Idlib province, near the border with Turkey, forced some 500 Syrians flee the country since Wednesday -- raising the number of people who sought refuge in Turkey to 8,900, according to Turkish authorities.

The stream of refugees has been an embarrassing public spectacle for Damascus, which has banned foreign journalists in order to control coverage of the uprising. This week, Syria appealed to the refugees to return to Jisr al-Shughour, saying the town is now safe.

But many refugees say they are not persuaded.

Speaking to The Associated Press from Turkey, a Syrian refugee who identified himself as Ali said troops were "firing at anything" in his hometown of Jisr al-Shughour.

Asked whether they heard the calls of the Syrian government to return home, he replied: "Do you believe that? They would kill us."