BELGRADE, Yugoslavia (AP) _ Opposition activists try to block key roads throughout the country. Policemen barricade themselves inside a radio and television station. Riot police club protesters.

After weeks of mostly peaceful protests, President Slobodan Milosevic and his opponents seem headed for a showdown.

The protests, now in their 10th week, erupted when the government annulled the results of Nov. 17 local elections in 14 communities won by opposition candidates.

Milosevic has since allowed his opponents to take power in a few of those towns, but he refuses to give up a key tool: the local news media he has used to criticize his opponents and censor the flow of information throughout the country.

Milosevic plans to use the news media to help him in Serbia's presidential and parliamentary elections later this year.

The city at the center of Thursday's confrontations _ Kragujevac, 90 miles south of Belgrade _ is one of the places where the opposition has been allowed to take power. The local news media is still in the hands of Milosevic allies.

``Kragujevac is boiling, and I don't know what the solution could be,'' said Borivoje Radic, the new head of city government.

Hundreds of policemen barricaded themselves inside the radio and television station to prevent its takeover by the new city officials.

Thousands of Milosevic's opponents surrounded them and threatened to use force to enter. Someone posted a sign on the building: ``This is a police station, not a radio station.''

Police also prevented an angry crowd of several thousand demonstrators from surging into a Kragujevac police station. At least 16 people were injured in clashes with police in the city.

Elsewhere in the country, police detained at least eight opposition activists who tried to block roads during protests. Wielding batons, the police officers beat protesters who parked their cars on the main road between Kragujevac and Belgrade. Two people were clubbed to the ground and at least one opposition leader was detained.

Police hit an Associated Press Television crewman in the stomach as he was videotaping the blockade. He and another crewman were briefly detained and their footage was confiscated.

Kragujevac's new mayor, Veroljub Stevanovic, said residents were furious because local policemen had beaten their own people.

``They are like robots: When they get an order they fulfill it,'' he said. ``It doesn't matter if the person out there is their brother or not.''

Local opposition leader Aleksandar Radosavljevic said talks to negotiate an end to the standoff at the television and radio station had failed, and that the protests would continue.

Police locked themselves inside the station on Wednesday, saying they were protecting the studios while a court considers an appeal by official Serbian media challenging its handover.

Ljuba Tadic, a Belgrade actor, urged protesters outside the building Thursday to remain patient.

``We will get the TV station even if it takes two, three or even six months,'' he said.

The city's new radio director, Vidosav Stevanovic, and the new mayor went to Belgrade today for talks with the general manager of official Serbian TV.

A city official in Kragujevac said he was skeptical the talks would accomplish much.

``When have they (the Socialists) ever returned anything to anybody?'' said Vlatko Rajkovic.

Rajkovic said Kragujevac's new authorities were ready for a compromise in which the old Socialist and new democratic managers would work together until the court issues a ruling on who controls the television.

In Belgrade on Thursday, opposition leader Zoran Djindjic urged a crowd of about 20,000 protesters to hold their ground.

``The whole of Serbia has risen,'' he said. ``We must not lose at any front, in Belgrade or anywhere else in Serbia.''