Venezuela's secret police have arrested a key opposition leader and are searching for two others in an apparent crackdown by President Hugo Chavez against leaders of a recent general strike designed to force him from office.

Carlos Fernandez, head of Venezuela's largest business federation, was arrested late Wednesday by about eight government agents outside an upscale restaurant in eastern Caracas. Fernandez was taken to the headquarters of Venezuela's secret police agency, the Directorate of Intelligence and Prevention Services. Opposition leaders say he is being held on charges of treason, "civil rebellion" and illegal assembly.

Government authorities are now searching for Carlos Ortega, the head of Venezuela's largest labor federation, who with Fernandez was prominent in the two-month strike that recently ended. Ortega called Fernandez's arrest a "terrorist act" and said he would not turn himself in.

Government officials said a third arrest warrant had been issued for Juan Fernandez, the former financial planning director at the state oil company, Petroleos de Venezuela, who led the strike at the company. He was fired by Chavez, along with about 13,000 other employees.

The new action appears to be part of a calculated retaliation by Chavez against the opposition movement just as the oil-rich country is showing signs of recovering from the crippling general strike. It also has complicated negotiations to end a political crisis that has shaken Venezuela for more than a year and raised the specter of fresh violence.

"These people should have been jailed a long time ago," Chavez said today at a ceremony at the Foreign Ministry.

Authorities this week discovered the bodies of three dissident Venezuelan army soldiers and an opposition activist in a killing characterized by international human rights groups as politically motivated.

The arrest of Carlos Fernandez came a day after government and opposition negotiators agreed to an eight-point declaration renouncing violence and inflammatory rhetoric as they seek a deal on new elections. The document was the first accord to emerge in three months of talks mediated by Cesar Gaviria, secretary general of the Organization of American States, who called on the government today to ensure that Fernandez receives an "independent, impartial" trial.

Thousands of Chavez opponents demonstrated today in response to Fernandez's arrest, many in front of the headquarters of Petroleos de Venezuela, where thousands of employees continue their walkout.

Chavez, a populist firebrand elected in 1998 on a pledge to help Venezuela's poor, survived a military-led coup last April that began with a strike in the oil sector. But an opposition movement made up of labor and business groups, leftist political parties, and middle- and upper-class civilians continued the effort to drive him from office.

Opposition leaders called a general strike on Dec. 2 to force Chavez to resign or move up presidential elections, scheduled for 2006, to this year. Chavez weathered the strike by creating a system that maintained food and gasoline supplies, but depleted the public treasury. The financially damaged private sector lifted the protest on Feb. 3.

Although workers at the state oil company remain on strike, the government says production has returned to more than half its pre-strike level of 3 million barrels a day. The company accounts for half the government's revenue and 15 percent of U.S. oil imports.

Jose Miguel Vivanco, head of the Americas division of Human Rights Watch, said Fernandez's arrest left him "extremely concerned by these retaliatory operations." Opposition members said at least one of the charges against Fernandez, civil rebellion, does not even appear in the criminal code.

"The risk here is that the government has decided to criminalize political expression and the actions of the opposition," he said.

The OAS talks are scheduled to resume Wednesday, giving both sides time to plan their next steps. Rafael Alfonzo, an opposition negotiator who represents Fedecamaras, the business federation that Fernandez heads, said, "Obviously, we must do something about this."

"Some [opposition] people complained when we signed the [nonviolence] agreement, but we believed in it," Alfonzo said. "Now we have this demonstration on the government's part that shows clearly that we do not have a democracy and freedom."

Members of Venezuela's secret police guard the entrance of the Caracas station where Carlos Fernandez, a leader of the recent general strike, was in custody after his arrest Wednesday. Labor federation leader Carlos Ortega is also being sought on charges stemming from the general strike, which ended Feb. 3 after failing to oust President Hugo Chavez. Ortega said he would not turn himself in.