Caracas, Venezuela: Venezuelan prosecutors say they have arrested the ruling-party mayor of a large city as part of a crackdown on corruption.

Sunday’s announcement from the national prosecutor’s office says Valencia Mayor Edgardo Parra was detained Saturday night. He has denied wrongdoing.

Officials earlier announced the arrests of two people suspected of fraudulent dealings with the city of about 2.2 million people.

President Nicolas Maduro has promised a crackdown on corruption, and has asked Venezuela’s Congress to give him special powers to carry out that fight. The global watchdog group Transparency International ranks Venezuela as one of the world’s most corrupt nations.

Critics have accused the government of using corruption allegations to target political foes, while protecting its allies. Parra is the most prominent pro-government figure so far detained in the crackdown

Meanwhile, opponents accuse the government of breaking anti-graft laws by failing to publish how it spends tens of billions of dollars in oil revenue.

This lack of disclosure makes it hard for investors, including those who hold Venezuela’s widely traded bonds, to measure state spending.

On Sunday, opposition leader Henrique Capriles called the “shameful” debate over decree powers a “political pantomime,” the only aim of which was to win more power for the president.

“How dare you tell us you’ll fight corruption, when the people guilty of stealing public funds are exactly the same ones you chose to govern with you?” he wrote in his weekly column.

Critics fear the president could use decree powers to push through laws that have nothing to do with fighting corruption.

Graft has been a problem in Venezuela for decades. By the 1990s, it had generated so much outrage among voters it helped sweep Chavez and his self-styled revolution into office.

Chavez passed nearly 200 laws by decree during his rule.

Maduro, who largely blames corruption on the opposition and private companies, denies there is any immunity. He repeatedly says he is the victim of US-backed plot to unseat him that ranges from “economic war” to sabotage and assassination plots.