Forces loyal to President Bashar al-Assad shot dead ten people on Tuesday in the Syrian city of Hama, activists said, and France called on the United Nations to adopt a firm stance in the face of "ferocious armed repression".
Tanks were still surrounding Hama, days after it witnessed some of the biggest protests against Assad's rule since a 14-week uprising erupted in March.
Troops raided towns to the northwest of Hama near the border with Turkey in Idlib province, and authorities intensified a campaign of arrests that has resulted in the detention of at least 500 people in the last few days, rights campaigners said.
In the eastern provincial capital of Deir al-Zor, security forces arrested Ahmad Tuma, a former political prisoner and secretary general of the Damascus Declaration, a grouping of opposition figures founded in 2005 to unify efforts to transform the country into a democracy.
"Heavily armed 'amn' (security police) came to Dr Tuma's clinic and dragged him away in front of his patients," one of Tuma's friends told Reuters by phone.
Some residents of Hama, scene of a crackdown by Assad's father nearly 30 years ago, had sought to halt any military advance by blocking roads between neighbourhoods with garbage containers, burning tyres, wood and metal.
Tuesday's raid by security forces and gunmen loyal to Assad followed the killings of at least three people when troops and security police entered Hama at dawn on Monday.
French MP Gerard Bapt, head of the French-Syrian Friendship Committee, told Reuters: "With the Arab League not moving and with a nation like Saudi Arabia saying nothing publicly to condemn the killings by the Syrian regime it is difficult to see international pressure rising beyond the economic."
France, unlike its European partners and the United States, says Assad has lost legitimacy to rule. But a French campaign for U.N. condemnation of the crackdown has met stiff Russian and Chinese resistance.
HAMA SYMBOLISM
"Assad may wait to see whether large-scale protests in Hama continue. He knows that using military aggression against peaceful demonstrations in a symbolic place like Hama would lose him support even from Russia and China," Syrian activist Mohammad Abdallah told Reuters from exile in Washington.
Assad's father, Hafez al-Assad, who ruled Syria for 30 years until his death in 2000, sent troops into Hama in 1982 to crush an Islamist-led uprising in the city where the Fighting Vanguard, the armed wing of the Muslim Brotherhood, made its last stand.
That attack killed many thousands, possibly up to 30,000, and one slogan shouted by Hama protesters in recent weeks was "Damn your soul, Hafez".
Rights groups say Syrian security forces have shot and killed at least 1,300 civilians across the country since the protests started and arrested over 12,000.
Several troops and police officers have been killed for refusing to fire at civilians.
Authorities say 500 police and soldiers have been killed by gunmen, who they blame for most civilian deaths.
Assad has promised a national dialogue with the opposition to discuss political reform in Syria, which has been under the iron rule of the Baath Party for nearly 50 years. Many opposition figures reject dialogue while the killings and arrests continue.
