SAN JOSE, Costa Rica (AP) _ A Dutch couple kidnapped more than three weeks ago in northern Costa Rica were freed unharmed Tuesday, radio and television reports said.

The reports quoted Manuel Alvarado, head of the Organization of Judicial Investigation, the Costa Rican equivalent of the FBI.

Huite Zijlstra and his wife, Jitty Koers, both 50, were taken from the Altamira de Aguas Zarcas ranch in the San Carlos district near the Nicaraguan border. The group behind the Aug. 24 abduction calls itself the Maria Felix Commando, and has demanded $1.5 million in ransom.

Alvarado said on Costa Rican television Tuesday night that a ransom was paid but he did not say how much. The hostages were undergoing medical checkups at a hospital near where they were freed.

There was an exchange of gunfire when police tried to capture the kidnappers, but apparently nobody was hit, Alvarado said.