Syrian soldiers and tanks carrying out a nationwide crackdown on regime opponents are reported to have surrounded the city of Hama.
President Bashar Assad's father crushed a revolt there in 1982.
Assad, who inherited power in 2000, is trying to smash an uprising that exploded nearly two months ago.
Human rights activist Mustafa Osso said troops backed by tanks have deployed around Hama, and security forces were detaining people.
In an echo of the earlier uprising, the Syrian army shelled residential areas in central and southern Syria yesterday, killing 18 people, a human rights group said.
The shelling of neighbourhoods evoked memories of Assad's father, Hafez, whose most notorious act was shelling Hama in 1982.
He levelled the city to crush a Sunni uprising. Up to 25,000 people were killed, according to Amnesty International estimates.
Other activists said security forces used clubs to disperse about 2,000 demonstrators yesterday at the university campus in Aleppo, Syria's largest city.
The intensifying military operation and arrest raids seemed to be an effort to pre-empt another day of expected protests throughout the country on Friday.
More than 750 people have been killed and thousands detained since the uprising against Assad's autocratic rule began in mid-March.
Syria's private Al-Watan newspaper reported today that Assad met for four hours with a delegation of Sunni clerics from Hama. It said the clerics asked the president to solve some problems pending since 1982, such as people who have been living in exile since then.
"President Assad accepted to study the case as long as it includes people who are known to be loyal to the nation," the paper said.
Since the uprising began, authorities have been making announcements about reforms on Thursdays in an attempt to head off protests on Friday, the main day for demonstrations in the Arab world.
This week the state-run news agency, SANA, said Prime Minister Adel Safar introduced a new programme to employ 10,000 university graduates annually at government institutions.
Unemployment in Syria stands at about 20 %.