Armenia's top investigative body said Wednesday that 23 people are now in custody on suspicion of organizing riots in the capital, Yerevan, during a two-week armed standoff.

Investigators say those arrested include the deputy chairman of the opposition Heritage party and the leader of the civic movement Rise Up, Armenia.

Armed men seized the police compound on July 17, demanding freedom for an opposition group leader who was arrested in June. That group, Founding Parliament, has sharply criticized the government of the former Soviet republic and called for people to take to the streets to force the president and the prime minister to step down.

All the gunmen inside the compound surrendered on Sunday, ending the standoff that left two police officers dead and several wounded on both sides.