Updated

The national guard broke up an opposition protest with tear gas and rubber bullets and chased away dissident Venezuelan generals Tuesday during an escalating strike to oust President Hugo Chavez.

In his first public comment since the strike began Monday, Chavez called the action "a desperate effort" to oust him by an opposition bent on "destabilization and violence."

"This strike, like all the others, has a hidden agenda: another coup attempt," Chavez told reporters. He vowed that "they won't achieve their sinister goals of destabilizing the country."

Chavez accused opposition thugs of harassing storekeepers to close their shops and provoking clashes with security forces. He vowed that the strike won't "paralyze" Venezuela's key oil industry, and he said he wasn't considering calling a state of emergency, as strikers claim.

Venezuela's energy ministry said late Tuesday that all oil refineries were producing at 100 percent capacity and that shipments were normal. Venezuela is the world's fifth-largest oil producer and a top U.S. supplier.

Chavez urged strike leaders to return to negotiations on elections, mediated by the Organization of American States.

But strike leaders extended their action indefinitely and called more street protests for Wednesday after the National Guard chased away protesters and roughed up several journalists.

Dozens of oil executives and their supporters, angered by the armed robbery of a top manager early Tuesday, called a rally at the headquarters of Venezuela's state-owned oil monopoly Petroleos de Venezuela S.A.

Soldiers swiftly cleared the protest from the area, which had been decreed an off-limits "security zone" by Chavez. They also chased away dissident generals who tried to convince them to let the protest proceed.

Hours later, troops withdrew to a nearby air force base. Thousands of protesters celebrated at PDVSA headquarters, banging pots and pans and blowing whistles. Others protested outside the air base but were chased away by tear gas.

Rafael Vargas, a top Chavez aide, said the government will not hesitate to crack down on protests.

"PDVSA is a strategic business. It's the heart of Venezuela. What happens to PDVSA happens to Venezuela," Vargas said.

Oil accounts for half of government income and a third of gross domestic product. The oil company managers are trying to halt oil operations and provide a critical boost to the general strike.

Elsewhere, police scuffled with strikers in western Venezuela, a base for the nation's oil industry. The navy chased away strikers in small boats trying to block a navigation canal in Lake Maracaibo used by tankers exporting 1 million barrels of crude each day.

Many oil managers were participating in the strike, but production at rigs and refineries appeared normal. Workers who had trouble getting to oil rigs because of boaters' strikes on Monday worked normally Tuesday.

Strike leaders said 75 percent of oil workers stayed home Tuesday. Labor Minister Maria Cristina Iglesias insisted only 18 percent stayed home. There was no way to reconcile the figures.

Venezuelans also kept a close watch on the military, which this fall has seen more than 100 officers rebel against Chavez. None of them command troops, and many were stripped of authority after Chavez was deposed for two days in an April coup.

An oil industry shutdown, a general strike and the killings of 19 people in an April 11 opposition march provoked Chavez's ouster on April 12 by dissident officers. Thousands of civilians rebelled when an interim government abolished the constitution, and Chavez was restored to power.

The United States appealed to the government and the opposition to return to peace talks led by OAS Secretary General Cesar Gaviria. Gaviria met with Vice President Jose Vicente Rangel on Tuesday and urged both sides to refrain from violence.

"I'm very worried, of course, and hope this is solved soon," U.S. Ambassador Charles Shapiro said after meeting with Gaviria. Shapiro also visited the presidential palace on Tuesday.

The government said talks could resume when the strike ended. The opposition said the strike will end when the government resumes talks.

In Caracas, hundreds more stores, banks, food shops and cafes opened for business on Tuesday, and downtown's traffic jams resumed. But many events — including Venezuela's treasured winter league baseball All-Star Game — were postponed.

The strike began after the Supreme Court voided a Feb. 2 nonbinding referendum on Chavez's rule, saying the five-member national elections council needed at least four votes for approval. The council said Tuesday it had voted 4-1 to prepare the referendum. Chavez insists the constitution allows only a binding vote halfway into his presidency, in August 2003.