|Protesters in Baniyas, a coastal city, have demonstrated in solidarity with Deraa [Reuters]
Syrian security forces have moved into central and coastal areas ahead of Friday prayers in a test of will for demonstrators determined to maintain protests against the rule of President Bashar al-Assad, Reuters news agency reported.
Tanks have taken up positions near the urban centres of Homs, Rastan and Baniyas in the past two day, as activists vowed a "Day of Defiance" on Friday to press a seven-week-old anti-regime campaign in which rights groups say 607 people have been killed and 8,000 others jailed or gone missing.
Troops were also deployed in the Damascus suburbs of Erbin, Saqba, Douma and in the town of Tel, north of the capital, the agency reported.
An activist, who asked to remain anonymous for his own safety, told Al Jazeera in a phone interview from Baniyas that the Syrian government was continuing to reinforce its forces, tanks and surveillance on Thursday.
"We are facing a sort of a cleansing war against the people of Baniyas," he said.
Another activist told the AFP news agency: "It looks like they are preparing to attack the town, like they did in Deraa.”
Elsewhere in Syria, activists said troops had arrested 300 people in a Damascus suburb.
The sweep in the suburb of Saqba came despite appeals from UN chief Ban Ki-moon, the United States, Italy and France for President Assad to end the deadly crackdown on anti-government demonstrators.
"They cut off communications before they came in," a resident told Reuters news agency. "There is no resistance. The demonstrations in Saqba have been peaceful. Scores of people have been arrested."
Al Jazeera was unable to verify independently the accounts of the crackdown.
In another Damascus suburb, Douma, many men were taken from their houses by security forces making rounds from one house to another on Wednesday, a resident told Al Jazeera, adding that children as young as 14 years old were arrested.
Meanwhile, Al Jazeera urged Syrian authorities to release Dorothy Parvaz, one of the Qatar-based channel's journalists, who has been detained since she flew in to Damascus last Friday.
With military operations appearing to be centred north of the capital on Thursday, the Syrian official SANA news agency quoted an official military source as saying the army had completed its mission to "chase elements of terrorist groups ... and to restore security, peace and stability" in the southern city of Deraa.
The city where Syria's seven-week-old uprising began had been under military siege for 11 days with Assad unleashing tanks and snipers to crush dissent.
A correspondent for AFP reported that about 350 soldiers travelling in around 20 armoured personnel carriers and a similar number of lorries all bearing photographs of Assad drove out of the city around 10am local time on Thursday.
AFP quoted General Riad Haddad, director of the military's political department, as saying the withdrawal would be done in phases and that life in the city would "return to normal".
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"The army will have pulled out of Deraa completely by the end of the day," he said.
Farhan Haq, a spokesperson for the UN, said on Thursday that a UN humanitarian team will be going to Deraa in the coming days following an phone appeal by the UN secretary-general to Assad.
Aid workers from the Red Cross and Red Crescent on Thursday delivered their first emergency relief supplies to Deraa, a spokesperson for the organisation said.
A convoy of two trucks carrying clean drinking water and two trucks with food and first aid material accompanied the team of 13 experts from the Syrian Red Crescent and International Committee of the Red Cross, the ICRC's Hicham Hassan said.
The neutral humanitarian agency had no immediate information on casualties in Deraa.
The US and Italy warned Syria on Thursday that it will face penalties and increasing isolation if it does not halt violence against demonstrators.
Hillary Clinton, the US secretary of state, said Syria had to know that there would be "consequences for this brutal crackdown."
Speaking at press conference with Franco Frattini, the Italian foreign minister, Clinton said the US is looking at boosting sanctions it has already imposed on Syrian leaders. Frattini said Italy would support similar measures by the European Union.
Last month, the US administration imposed financial penalties on three senior Syrian officials, including Assad's brother, Maher, as well as Syria's intelligence agency and Iran's Revolutionary Guard over the crackdown.
France is working with its EU partners on implementing sanctions against Syrian leaders but there is still no agreement on who should be on the list, Alain Juppe, the country's foreign minister, said on Thursday.
"In the European Union, there exists the will to adopt sanctions quite rapidly," he told reporters after a meeting of an international contact group ranged against Libyan leader Muammar Gaddafi.