A human rights group says Syria transferred prisoners to military facilities in order to hide them from Arab League observers now visiting the country, while state media has announced the release of hundreds of prisoners.

New York-based Human Rights Watch said the Arab League should insist on gaining access to any detention site and must speak out when Syria prevents the monitors from doing their work.

The group said perhaps hundreds of prisoners were transferred shortly before the arrival of the observers, who are monitoring government pledges to withdraw troops, release political prisoners and halt violence.

Syrian state media said Wednesday the government released 755 prisoners who were arrested during the nine-month uprising against President Bashar al-Assad, and that those released did not commit acts of violence against fellow Syrians.

The head of the Arab League mission in Syria, Sudanese General Mohammed Dabi, said Wednesday the observers were due to travel to three new areas, including Hama, Idlib and Daraa.

Those visits follow a trip Tuesday by monitors to the city of Homs, where Syrian security forces fired tear gas to disperse tens of thousands of protesters.

The London-based Syrian Observatory for Human Rights said about 70,000 anti-government protesters marched toward the city center when security forces confronted them. Demonstrators chanted calls to execute Mr. Assad.

The Observatory confirmed amateur video showing troops also fired live ammunition on demonstrators in Homs. It said six people were killed in the city Tuesday, among 15 protest-related deaths nationwide.

The activists said violence continued Wednesday, with army defectors killing at least four government soldiers and wounding 12 others in Daraa province.

The United States on Tuesday condemned the recent violence in Syria, saying the government's actions go against its agreement with the Arab League. The State Department said Tuesday that if Syria continues to ignore the Arab League's efforts, the international community will consider other ways to protect civilians.

Rights groups have questioned whether monitors can work independently and if the relatively small number of observers will render the mission ineffective. Initially 500 monitors were to have entered Syria, but now only 150 are likely to be allowed into the country.

Middle East analyst Jonathan Adelman of the University of Denver told VOA the Arab League is hoping to push Mr. Assad away from fighting and into negotiations, but that the size of the observer mission is too small.

Fifty observers and 10 other Arab League officials arrived in the capital, Damascus, on Monday.

Syrian authorities agreed to the Arab League observers under international pressure and threats of Arab sanctions. The plan requires Syrian authorities to give the monitors freedom of movement everywhere except sensitive military sites.

The United Nations estimates 5,000 people have been killed since March in violence linked to Syria's unrest. Syria says armed terrorists are driving the revolt. It accuses them of killing 2,000 security personnel since March.