CARACAS, Mar. 20 (Reuters) - Venezuela attorney general Tarek Saab said on Wednesday that two people close to opposition candidate Maria Corina Machado had been arrested, prompting Machado to call the charges leveled at her team "completely false."

The arrests are set to complicate an already-confused scenario ahead of the July presidential contest. Machado won the opposition's October nominating contest by a landslide, but is barred from registering her candidacy.

Machado has been polling far ahead of Venezuelan President Nicolas Maduro, who is seeking re-election to another six-year term.

Seven other members of Machado's team, including her right-hand Magalli Meda, also have warrants out for their detention.

Washington called the move an attack on civil society and said it was inconsistent with the election guarantees deal inked last year that had led the U.S. to relax some sanctions.

"We condemn the arbitrary arrests and warrants issued today for members of the democratic opposition in Venezuela," Brian Nichols, assistant secretary for Western hemisphere affairs at the U.S. State Department, said on social media. "We call for the immediate release of these individuals and all those unjustly detained."

Machado told journalists in Caracas the arrests would not weaken her.

"If the regime believes that with these actions they're going to isolate me, that they're going to cut me off, be very clear - our team is Venezuela," she said.

Supporters in the international community will have to deliver "much more than kind wishes" following the arrests, she added.

Washington has already warned it will allow oil sanction relaxations to expire in April if the socialist government of Maduro does not allow free and fair elections.

Henry Alviarez, the national coordinator of Machado's Vente Venezuela party, and Dignora Hernandez, the party's political secretary, were detained for alleged involvement in planned conspiracies and street violence, Saab said on state television.

"The public ministry asked for nine arrests, two have been carried out," Saab said.

There had been an arrest warrant issued for Alviarez in December, but it was withdrawn soon after a U.S.-Venezuela prisoner swap in which some opposition figures, as well as detained Americans, were freed.

Four other Machado campaigners have been arrested over the last three months on conspiracy accusations, among other alleged crimes.

With no sign that her ban will be lifted before the July 28 contest, opposition parties have been pressuring Machado to name a substitute who can register by a March 25 deadline. Meda was one of the people floated as a possible alternate.

In polling on the election, various opinion polls have forecast Machado, 56, would pick up at least 50% of votes, while Maduro, a 61-year-old former bus driver who has been president since predecessor Hugo Chavez died in 2013, was projected to receive around 20%.

But Venezuela's top court upheld her ban in January, imposed over her support of U.S. sanctions and accusations of corruption that Machado says are an attempt to prevent a democratic vote.

In response, the United States has started re-imposing sanctions and warned about the April expiry of oil sanctions relaxations.

A Washington official said this week the U.S. is still holding out for progress, but Caracas had been sending "negative signals."

Photo from Reuters