Venezuelan opposition leader and self-proclaimed interim president Juan Guaido talks to the media before a session of the Venezuela’s National Assembly in Caracas, Venezuela January 29, 2019. REUTERS/Carlos Garcia Rawlins

CARACAS (Reuters) - Venezuela’s chief prosecutor said on Tuesday he had asked the Supreme Court to open a preliminary investigation into self-proclaimed interim president Juan Guaido, as well to freeze the opposition leader’s accounts and impose a travel ban on him.

The United States, along with several countries around the world, have recognized Guaido as Venezuela’s legitimate head of state and denounced leftist President Nicolas Maduro as a usurper. Maduro, sworn in earlier this month for a second term after disputed elections last year, accuses Guaido of staging a U.S.-directed coup against him.

Attorney General Tarek Saab said on state television said he had asked the court “to open a preliminary investigation into Mr Juan Guaido as a result of diverse violent occurrences provoked in this country since Jan. 22,” the day before Guaido named himself president.

He also accused Guaido of helping foreign countries to interfere in internal matters.

As a lawmaker, who also heads the National Assembly, Guaido has immunity from criminal investigation that can be removed only by a high court.

Minutes after the announcement, Guaido said he did not underestimate a threat of imprisonment but did not believe it was “anything new.”

“We are here, we will keep acting and working to confront the humanitarian crisis,” he told a news conference.

Hundreds of thousands of people protested on Jan. 23 against Maduro, triggering a police crackdown. At least 40 people are believed to have been killed in political violence last week, including 26 shot by pro-government forces, the United Nations said on Tuesday.

Stepping up the pressure on Maduro, the administration of U.S. President Donald Trump imposed sanctions on Venezuelan state-oil firm PDVSA on Monday, triggering higher global oil prices and angry responses from China and Russia.