Venezuelan electoral officials are going ahead with an audit of votes from Sunday's recall referendum in which President Hugo Chavez was declared the winner. Tensions remain high, however, as opposition leaders refuse to participate as witnesses to the audit and continue to denounce the results as fraudulent. Meanwhile, police say they have arrested two of the three gunmen who fired on an opposition rally Monday, killing one person and wounding eight others.

As reporters and photographers crowded around, police escorted one of the men accused in the shooting incident to jail. The man, who resembles one of the gunmen seen in photographs from the crime scene, refused to answer reporters' questions as to what political group he might be affiliated.

The police action came only days after President Chavez denounced the shooting and promised that authorities would take action against the perpetrators. Mr. Chavez rejected opposition claims that the shooters were associated with his government or with groups who support him.

Also on Wednesday, the head of the Venezuelan Electoral Council, Jorge Rodriguez, told reporters that the audit being conducted by the council under the supervision of international observers should be complete before the end of the week. The audit is being based on 150 vote boxes selected at random from the 24 electoral districts. Auditors will check paper ballots against the count provided by electronic machines that were used to tabulate the final vote count.

Mr. Rodriguez says there is no foundation for opposition claims that the machines were programmed to favor the pro-Chavez vote.

He says the machines were never reprogrammed once they had been prepared for the election. He says accusations of electronic fraud come from a sector that was defeated in the election and is having trouble accepting it.

But opposition leaders remain defiant, calling on Venezuelans to reject the election results. One of the principal opposition leaders, Enrique Mendoza, the governor of Venezuela's Miranda state, says the opposition umbrella group, called the Democratic Coordinator, is boycotting the electoral audit.

He says no one from the opposition will attend the vote audit at the electoral council center and he calls on opposition representatives from around the country to stay away from any activity associated with the audit.

Mr. Mendoza and other opposition representatives say the audit of paper ballots is useless since the ballots came from the same machines that were programmed to fix the vote in favor of Mr. Chavez.

But the opposition finds itself increasingly isolated both here in Venezuela and internationally. The Secretary General of the Organization of American States, Cesar Gaviria, and former U.S. President Jimmy Carter, both of whom observed the election process Sunday, say they have seen no credible evidence of fraud. They asked for the audit in order to meet concerns expressed by the opposition, but they made it clear that they remained confident in the results announced by the electoral council on Monday.

Most nations in Latin America and Europe have announced their satisfaction with the electoral process and have accepted the Venezuelan election results. The U.S. State Department has also endorsed the results, although a spokesman cautioned that every effort should be made to investigate opposition complaints.