An armed group took over the high court while its justices were meeting in plenary session. A court spokesman said the Chief Justice, Edgar Cervantes, and 19 other judges were captive inside the building. 'The situation is very critical,' a spokesman said. He said the group identified itself as 'Death Commando', but there was no immediate indication of what its demands were.
Only two of the court's 22 justices were not taken hostage, according to the spokesman, who said they arrived late for the meeting.
Police surrounded the building as employees were evacuated from the courthouse in the centre of the capital, San Jose.
The Security Minister, Luis Fishman, and the presidential chief of staff, Rolando Lacle, met to discuss the situation with officials of the Red Cross and the fire department.
The incident comes only weeks after armed commandos opposed to Nicaragua's Sandinistas seized the Nicaraguan embassy in Costa Rica and held the ambassador and other diplomats hostage for 13 days.