The Maduro-allied court is investigating opposition politicians on suspicion of treason. Meanwhile, the United States said it would lift sanctions on a former intelligence chief who came out in support of the opposition.
Venezuela's Supreme Court, which is closely allied with President Nicolas Maduro, said on Tuesday that it was launching a preliminary investigation into seven top opposition politicians. They are accused of treason, rebellion, and conspiracy in connection with the failed uprising of self-proclaimed interim President Joan Guaido.
Amongst those targeted in the probe are prominent lawmakers Henry Ramos Allip and Luis German Florido.
The case now goes to the attorney general and the Constituent Assembly, a parallel legislature set up by Maduro and his allies to cement his grip on power. The National Assembly, the longstanding legislature controlled by the opposition, has argued that the move violates the parliamentary immunity of lawmakers.
The Constituent Assembly has said it will strip the immunity of any lawmakers who backed the April 30 coup attempt.
Attorney General Tarek William Saab said separately that 18 arrest warrants have been issued for "civilians and military plotters" tied to the uprising.
Earlier on Tuesday, Guaido met with diplomats from some of the more than 50 countries who support his cause to oust Maduro. Russia, China, and Cuba remain staunch defenders of Maduro, who has yet to act directly against his rival, perhaps fearing intervention from the United States.
US lifts sanctions on ex-intel chief
Guaido has repeatedly called on the military and senior members of the Maduro government to back him, but only a few officials have defected.
US Vice President Mike Pence said Tuesday that the United States would lift sanctions it placed on former intelligence chief General Cristopher Figuera after he came out in support of Guaido.
Maduro fired Figuera last week as head of the SEBIN intelligence agency. He had been one of about 150 Venezuelan government officials targeted by US sanctions.
"The United States of America will consider sanctions relief for all those who step up for the constitution and support the rule of law," Pence said.
"I hope the actions our nation is taking today will encourage others to follow the example of General Cristopher Figuera," he said.
amp,es/jm (AP, AFP, dpa)