BEIRUT -- Syrian soldiers and tanks executing a nationwide crackdown on regime opponents surrounded the city of Hama on Thursday, which President Bashar Assad's father laid waste to in 1982 to stamp out an earlier uprising, an activist said. Forces also used clubs to disperse 2,000 demonstrators on a northern university campus.

Assad, who inherited power from his father in 2000, is trying to crush an uprising that exploded nearly two months ago and is now posing the gravest threat to his family's 40-year ruling dynasty. The level of violence is intensifying as forces move into more volatile areas, and the United States called the crackdown "barbaric."

Human rights activist Mustafa Osso said troops backed by tanks have deployed around the central city of Hama, known for the bloody 1982 revolt crushed by the regime, and security forces were detaining people.

In another echo of that earlier uprising, the Syrian army shelled residential areas in central and southern Syria on Wednesday, killing 18 people, a human rights group said.

The shelling of neighborhoods evoked memories of Assad's father and predecessor, Hafez, whose most notorious act was shelling Hama in 1982.

He leveled the city to crush a Sunni uprising there, killing 10,000 to 25,000 people, according to Amnesty International estimates. Conflicting figures exist and Syria has made no official estimate.

Other activists said security forces used clubs to disperse about 2,000 demonstrators late Wednesday 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. The revolt was touched off by the arrest of teenagers, inspired by uprisings in Egypt and Tunisia, who scrawled anti-regime graffiti on a wall.

Syria's private Al-Watan newspaper reported Thursday 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 was no different: The state-run news agency, SANA, said Prime Minister Adel Safar introduced a new program to employ 10,000 university graduates annually at government institutions.

Unemployment in Syria stands at about 20 percent.

Rami Abdul-Rahman, director of the Syrian Observatory for Human Rights, said Thursday that arrests are continuing throughout the country before expected protests on Friday.

"Authorities are detaining any person who might demonstrate," he said.

In the northern city of Deir el-Zor, authorities placed cameras inside and outside the Osman bin Afan mosque, where many worshippers were demonstrating after the Friday prayers, he said.

Abdul-Rahman added that many former detainees were forced to sign documents reading that they were not subjected to torture and that they will not take part in future "riots."

Assad is determined to crush the uprising despite international pressure and sanctions from Europe and the United States.

In Washington, White House press secretary Jay Carney condemned the violence. "The Syrian government continues to follow the lead of its Iranian ally in resorting to brute force and flagrant violations of human rights and suppressing peaceful protests," he said, "and history is not on the side of this kind of action."

State Department spokesman Mark Toner called the Syrian attacks "barbaric," adding, "We don't throw the word 'barbaric' around here very often."

Officials in the Obama administration, which had sought to engage Syria after it was shunned under former President George W. Bush, said Tuesday the U.S. is edging closer to calling for an end to the long rule of the Assad family.

The officials said the first step would be to say for the first time that Assad has forfeited his legitimacy to rule, a major policy shift.