Damascus: UN Secretary General Ban Ki-moon denounced on Wednesday the "escalating violence" in Syria, and called on authorities there to "immediately" stop the bloody repression.

His remarks came as a pro-government newspaper said troops had swept through the central city of Homs, where at least 50 people have been killed in four days of violence, arresting "armed men" and confiscating "stockpiles of weapons."

"The Secretary General is following with deep concern the escalating violence against peaceful protesters in Syria," said spokesman Martin Nesirky, who called on the Government to "stop the repression immediately."

"The Secretary General reiterates his call for a credible and inclusive dialogue, which should be carried out without delay," Nesirky said.

A newspaper said "an uneasy calm has reigned in Homs since Tuesday afternoon after top-quality operations by the army, who arrested a number of armed men and seized large quantities of weapons.

There were "bloody clashes" that left "soldiers and an officer wounded," it said.

Al-Watan added that the "dialogue launched by civic leaders had resumed in a bid to contain dissent and re-establish unity," in Homs, 160 km (100 miles) North of the capital.

Activists say pro-regime gunmen have killed at least 20 people in Homs since Monday, including seven mourners at a funeral.

Shots were heard in Homs Wednesday as security forces surrounded the city and arrested 150 people, Abdel Karim Rihawi of the Syrian League for the Defence of Human Rights said on Wednesday.

Fierce fighting rocked Homs at the weekend, with activists reporting more than 30 people killed in clashes among Christians, Sunni Muslims and President Bashar al-Assad's minority Alawite community.