(CNN) -- Syrian security forces arrested two people outside of the University of Damascus Wednesday as student demonstrators rallied for the release of political detainees, eyewitnesses told CNN.
Army convoys and tanks rolled into the capital city, setting up what eyewitnesses described as a base in the central square.
"The army knows they cannot pressure the economic situation too much in Damascus. Everyone is trying to go about their work, school and their businesses," one eyewitness activist told CNN.
Amnesty International said it has received first-hand reports of torture and other ill treatment from detainees held in Syria, as a wave of arrests of anti-government protesters intensified over the weekend.
Amnesty International said "widespread, arbitrary arrests" had taken place in towns across the country in recent days. At least 499 people were detained Sunday during house-to-house raids in Daraa, a key location for pro-reform protests, the group said, adding that most were being held at unknown locations without access to lawyers or their families.
The rights group also said it had the names of 54 people killed last Friday, which brought to 542 the number of people killed during a month and a half of protests in Syria. Amnesty International stated in a report that the high number of deaths can be attributed to tactics by Syrian security forces.
The group gave the accounts of two men detained last month in the coastal city of Banias.
One detainee said he was forced to "lick blood off the floor" after being stripped and beaten, Amnesty International said in a statement. The man told the group that he and and others detained with him had been beaten with sticks and cables as well as kicked and punched.
The rights organization said the detainee also reported being held for three days without food and being forced to drink dirty water from a toilet.
"These disturbing new accounts of detainees being tortured further underscore the need for President Bashar al-Assad to put an end to his security forces' violent onslaught against his own people," Philip Luther, Amnesty International's deputy director for the Middle East and North Africa, said in a statement.
"The use of unwarranted lethal force, arbitrary detention and torture appear to be the desperate actions of a government that is intolerant of dissent and must be halted immediately. Syrians must be allowed to voice their calls for change peacefully," he added