(CNN) -- At least one person was critically injured Tuesday in Venezuela when police clashed with opponents of the government of President Hugo Chavez.
According to CNN affiliate Globovision, violence erupted in the municipality of Mario Briceno Iragorry, in Aragua state, when the opposition tried to stop officers from confiscating election documents including voter lists.
A man who was run over by a police tow truck was taken to the hospital in serious condition, Globovision said. The TV news network also reported that the man in charge of the local electoral board was detained.
Acting on a ruling earlier Tuesday by Venezuela's Supreme Court, Aragua police had confiscated lists of voters who participated in Sunday's primary elections. The court had ordered that the lists be confiscated so that electoral authorities could use them to investigate alleged irregularities during Sunday's elections.
According to the Venezuelan government, the court acted after a candidate who participated in the primaries complained his rights had been violated. The Venezuelan Ministry of Communication identified him as Rafael Velasquez, a candidate for mayor in the town of Yaracuy.
"I have the right to ask for the voter lists to be reviewed," Vasquez said, according to a statement published by the ministry. "I'm asking for what is right. There were irregularities. I saw a polling place where there were more votes cast than voters who showed up to vote."
But opposition leaders, including Bolivar state governor Pablo Medina, cried foul, saying the court's ruling was an effort by the Chavez government to intimidate voters who participated in the primaries.
Medina called the decision to confiscate the voter lists tantamount to "state terrorism" and told Globovision it would not stop the opposition from defeating Chavez in the October 7 presidential elections.
"We're not afraid of what they may do," Medina said about government officials' possible reactions. "Above their actions, above the Supreme Court, above the government, above those institutions that have been sequestered, we're going for total victory on October 7 in order to transform Venezuela into a democratic country."
Opposition leaders cited the publication in 2003 and 2004 of the names of thousands of Venezuelans who had petitioned for Chavez to be recalled. Many of the names of those who appeared in the so-called Tascon List were subsequently targeted by the Chavez government, the opposition leaders said.
Luis Tascon was a pro-government legislator who posted on his website the names of people who had signed a petition to remove Chavez. His said his rationale was that a Venezuelan could look at the postings to determine whether his or her signature had been forged.
But a study published last April in the American Economic Journal: Applied Economics supported the concerns of the opposition. Lead author University of Chicago economist Chang-Tai Hsieh concluded that signers of the 2003 recall petition whose names were subsequently made public saw their earnings drop by 5% on average and their employment probability drop by 1.3% when compared to those who did not sign the petition. That finding "is strongly suggestive that the main instrument of political retaliation" was the widely circulated database that contained the list of signers, the authors concluded.
Opposition attorney Omar Arevalo told Globovision that he was surprised when he saw the court's ruling. By law, Arevalo said, the voter lists are supposed to be destroyed as early as 48 hours after the election, which expired Tuesday.
"We had a commitment since before the February 12 primaries to destroy the lists by burning them. This was to protect the identities and the rights of (opposition) voters because our country has lived very regrettable situations like the Tascon List," Arevalo said.
More than 3 million voters participated in Sunday's primary elections, twice as many as expected. Henrique Capriles Radonski, the 39-year-old governor of Miranda state won the primary with more than 60% of the vote.
Capriles will run for the presidency against the incumbent Chavez, who has been in power for 13 years.
In a statement, the opposition group Unity Venezuela said many of the records had already been destroyed.
The group's executive secretary, Ramón Guillermo Aveledo, said lawyers were "already studying" ways to oppose the Supreme Court's decision, which he called "absurd, unconstitutional and disproportionate."