Local media reported that the central square in Nis, Serbia's third-biggest city, was blocked for about an hour as 400 reservists demanded back pay, free electricity and rent. They pledged to return today and continue the protests until their demands are met.
In Krusevac, 95 miles south-east of Belgrade, about 200 reservists staged a similar protest, the private Beta news agency reported.
"We want nothing more or less than what the Interior Ministry troops received in Kosovo," Beta quoted the leader of the group in Nis, Miodrag Stankovic, as saying. "They got all the money, while we bled for three months for nothing."
The special police troops Mr Stankovic referred to are considered close to the Yugoslav President, Slobodan Milosevic. They are widely blamed for the worst atrocities against ethnic Albanians in the Kosovo conflict.
Since the end of Nato's bombing campaign, thousands of returning army reservists have been blocking roads and demanding back pay totalling the equivalent of about pounds 64m.
The reservists' protests are considered even more dangerous for Mr Milosevic than calls for his ousting at daily opposition rallies over the past two weeks, as the soldiers could trigger an army mutiny.
Some 8,000 opposition supporters carrying anti-Milosevic banners cheered their leaders at the start of a protest rally yesterday in the central Serbian town of Kraljevo. The rally is the latest in a series organised by the opposition umbrella group, Alliance for Change.
The opposition is trying to forge a united front, after failing to capitalise on public discontent with Mr Milosevic. Yesterday, the Alliance for Change signed an agreement on joint action with another coalition, the Union of Democratic Parties. Vladan Batic, a spokesman for the Alliance, said at the signing that they would try to "channel in a right way the dissatisfaction of Serbs against the current regime".
The most popular opposition leader, Vuk Draskovic, has so far refused to join the others. He plans a separate anti-Milosevic rally in the industrial town of Kragujevac today.
The neo-communist Yugoslav Left Party, run by Mr Milosevic's wife, Mirjana, said the opposition rallies represent "continuation of the Nato aggression". (AP)