Venezuelan opposition leaders called Saturday for mass protests on December 1 against President Nicolas Maduro’s contested reelection, as his government claimed it had uncovered another alleged “destabilization” plot and made arrests. “We have to act now,” opposition leader Maria Corina Machado said in a virtual meeting with other activists. She said mass demonstrations would be held in Venezuela and abroad on December 1, and promised “more decisive action” ahead of January 10, when the next presidential term is set to begin. Machado claims that her party’s candidate, Edmundo Gonzalez Urrutia, soundly defeated Maduro in the July 28 vote, an assertion backed by several nations, including the United States. Venezuela’s election authorities have proclaimed Maduro reelected to a third consecutive term, while refusing to release detailed voting data. Prosecutors on Friday opened a treason investigation into Machado, who has been in hiding, accusing her of supporting US sanctions against the country. In the wake of the contested election, anti-government protests saw at least 28 people killed, with hundreds injured and thousands arrested in crackdowns. Authorities subsequently launched investigations of opposition leaders and an arrest warrant was issued for Gonzalez Urrutia. He fled to Spain but has promised to return to be sworn in as president on January 10. “There is no doubt about that,” he said in the virtual meeting. “We are fighting, we are taking our voice — the voice of all Venezuelans — abroad,” he said, adding that he had found “great receptivity” to the opposition cause during visits to Portugal, Italy and Belgium. Maduro’s interior minister meanwhile announced Saturday that three judges, a prosecutor and a soldier had been arrested for participating in an alleged conspiracy to overthrow the government. “There is a new conspiracy, a new operation against the country, a new destabilization operation” based in northwestern Zulia state, Diosdado Cabello told reporters. Cabello asserted that paramilitary groups were being trained in Colombia and Ecuador to attack Venezuela. According to him, the five people detained Saturday have “direct links” to Machado and other opposition figures. The government has frequently denounced what it calls plans to destabilize the country. The United States, which has consistently said Gonzalez Urrutia won more votes than Maduro, referred to him this week for the first time as Venezuela’s “president-elect,” a move later followed by Italy.