CARACAS, Venezuela (AP) — Venezuela’s leading opposition party says a group of armed men with their faces covered raided its headquarters, taking cellphones, computers and ID cards from staffers and raising tensions the night before a nationwide protest against President Nicolás Maduro.

Popular Will members said Juan Guaidó, who belongs to the party, was not inside at the time. Staffers said they believe the men were some kind of government or security officers, though they didn’t identify themselves or show a court order.

Guaidó arrived at the 18th-floor office in Caracas minutes later and called for an end to Maduro's “dictatorship.”

He launched a campaign this year as head of the National Assembly to oust Maduro, backed by the U.S. and more than 50 other nations.

Maduro has not commented on Friday’s incident.