CIUDAD HIDALGO, Mexico (AP) _ At least 200 opposition politicians were arrested at city halls across western Michoacan state to end sit-ins protesting purported election fraud by the governing party, officials said Friday.

A government official called the opposition leaders, arrested Thursday and Friday at 17 city halls, ''a group of thugs.''

Cuauhtemoc Cardenas, founder and leader of the Revolutionary Democratic Party (PRD), said in a statement Friday that his party is ''in full rebellion.'' His party claimed soldiers and police arrested and beat at least 100 supporters in evictions Thursday at occupied town seats.

Party leaders claim the Institutional Revolutionary Party, which has been in power in Mexico for 61 years, cheated them out of victory in the Dec. 3 elections in both Michoacan and neighboring Guerrero state.

Soldiers in riot gear patrolled the streets of Ciudad Hidalgo, 120 miles northwest of Mexico City, in army trucks Friday afternoon, while police reopened city hall and ushered the mayor inside.

Eight PRD leaders were arrested in Ciudad Hidalgo during ''Operation Supreme Government,'' a Federal Judicial Police commander said. The official, who spoke on condition of anonymity, said similar arrests took place in all the towns where police removed protesters from city halls Thursday.

Participating federal agents arrested five of the opposition leaders at the central square in Ciudad Hidalgo after one of them, Arnulfo Medina, told The Associated Press the party planned to retake the city halls.

The arrest toll climbed to at least 200 on Friday, District Attorney Carlos Pratts told the Excelsior news service.

State Attorney General Color Romero denied charges that violence occurred in the arrests.

A federal government spokesman, who spoke on condition of anonymity, said Cardenas' remarks prove his party ''is not a political party, but rather a group of thugs, with its only law being the law of the jungle and savagery.''

Police installed mayors Friday in all the cleared city halls, a police officer in Ciudad Hidalgo said.

PRD spokesman Gustavo Tena said party members had organized a demonstration for Friday night in Morelia, the state capital. They were demanding authorities pull the army from Michoacan, end repression and free purported political prisoners.

Cardenas said Friday that supporters in Guerrero will also redouble their efforts to organize ''when the time is right.''

His party has called for the impeachment of Guerrero Gov. Francisco Ruiz Massieu and a ''return to order'' in that state after at least seven people died in February and March police actions to still protests.

Opposition activists stayed put at four city halls Friday, including Uruapan, where elections are scheduled to be repeated June 8, a state government spokesman said. He said protesters abandoned one city hall without police intervention.