Venezuelans prepared for protests on Friday to condemn the surprise arrest of Caracas’ mayor for allegedly plotting to overthrow the socialist government of President Nicolás Maduro.

Security forces dressed in camouflage and with weapons drawn entered Mayor Antonio Ledezma’s office late on Thursday and hauled him away amid protests by his aides. The detention, recorded by security cameras, set off a wave of outrage and spontaneous demonstrations, with Venezuelans, especially in middle-class enclaves loyal to the opposition, banging pots and pans and blaring their car horns.

Ledezma was expected to appear in court on Friday. His lawyers said they’re so far unaware what charges will be presented against him.

The arrest of the 59-year-old mayor, one of Maduro’s fiercest critics, comes amid a growing political and economic crisis years in the making but made worse by a recent tumble in oil prices, which funds the bulk of government spending.

Maduro in recent weeks has taken to the airwaves to denounce what he alleges was a US-backed coup intended to coincide with the anniversary of 2014 anti-government protests that caused more than 40 deaths. He’s also rounded up retail executives he blames for trying to sabotage the economy by hoarding basic goods and encouraging long lines outside supermarkets.

On Thursday night, Maduro went on national TV to denounce Ledezma as a “vampire” and accused him of conspiracy but stopped short of detailing any wrongdoing.

Ledezma’s arrest may be the boldest step in recent actions against the opposition, but is unlikely to rattle Maduro’s core base, which is better organized and more at ease when confronting a crisis, according to David Smilde, a Venezuelan researcher and senior fellow at the Washington Office on Latin America.

“The 20% that are left (supporting Maduro) are pretty hardcore and Ledezma is not a likable character,” Smilde said.

The embattled president could also be gambling that the allegations of a coup will enable him to distract attention from mounting woes such as 68 percent inflation and widespread shortages and weaken the opposition enough to allow him to prevail in legislative elections slated for later this year.

But the growing crackdown is not without risks. Opponents, who seemed lifeless in recent weeks even as the country’s problems have worsened, are enraged and Smilde says international pressure on Maduro is likely to increase. Already the US and international human rights groups have condemned the arrest.

Ledezma has been a thorn in the side of the ruling party since he was elected mayor in 2008, beating out a member of the socialist party led by the late President Hugo Chavez. The government subsequently transferred most of his powers to a newly created office run by a loyalist.

He joins another former mayor Leopoldo Lopez, who was arrested in February 2014 for allegedly inciting the violent protests.

Government critics say that as the administration loses strength, it is becoming more dangerous.

“We are going to see new provocations and aggressions,” Jesus Torrealba, spokesman for Venezuela’s opposition coalition, told reporters.