More than 700 Argentine police protesters demanding better pay and restoration of jobs occupied the provincial police communications center in the northern Argentine city of Posadas but the government showed no sign of seeking a compromise.
The protests were joined by firefighters and retired police officers in a dispute threatening to snowball into a wider challenge to Argentine President Cristina Fernandez de Kirchner.
Police frustration with inconclusive negotiations on higher pay has combined with anger over the government refusal to relent on demands by police to form trade unions to protect their rights.
Critics say low pay breeds corruption and has spread disaffection in police ranks.
Protesters said more police officers would join in the occupation till the demands were met.
Outside the Comando Radioelectrico building in central Posadas, friends and relatives of the protesting officers gathered in a camp and mounted an all-night chanting session in support of the police officers' demands.
The protest started Tuesday night when about 300 police officers broke into the police center after senior authorities refused to budge on demands to lift the suspensions of seven men accused of trying to unionize the force.
After the occupation began more police officers joined in, including many from outlying areas.
Several senior police administrators and a judge visited the occupiers but failed to persuade them to vacate the premises. The administrators also ruled out an end to sanctions against the seven officers.
The protesters want a salary floor of about $500 a month, new uniforms and equipment to replace what they consider obsolete gear.
However, their demand for creating a provincial police union has caused much sensitivity in Buenos Aires while the government grapples with protests by farmers, business groups and war veterans over various grievances.
Veterans' protests in Buenos Aires left the former soldiers and police bitterly polarized.
Many of the veterans are unhappy over alleged government neglect of their demands.
Among the protesters are former soldiers who were mobilized for the 1982 war with Britain over Falklands but were never deployed to the conflict. As a result, they say, they are treated differently from war veterans who went to the Falklands and don't receive any pension.
Argentina under military rule invaded the islands in 1982 but was repulsed by Britain in a 74-day conflict. The war cost the lives of 649 Argentine troops, 255 British troops and three Falkland Islanders.
Tensions over the police and service personnel's demands have boiled over before the 30th anniversary of the conflict.