Colombia's rebel group, the National Liberation Army (ELN), has released 33 people kidnapped from a church service last month, as the guerrillas search for a place in current peace talks.

The victims were kidnapped from La Maria church in a rich suburb of the city of Cali on 30 May.

The exact number still being held is uncertain, but believed to be over 20.

Over 140 people - including the priest - were originally taken from the church during the Sunday morning service by 30 armed guerrillas, who ushered them into two waiting trucks.

Over 80 were abandoned as the fleeing guerrillas came under pressure from pursuing security forces.

The rebels continued with the remainder, estimated at around 55, moving them on foot into the jungle-covered mountains south of Cali, where they disappeared.

The anti-kidnap group Fondation Pais Libre (NGO) said that families of some of the richer hostages taken from the church had received ransom demands, making it unlikely they would be released with the others.

Peace talks

The ELN has agreed to free hostages taken from three mass kidnapping operations in return for government concessions granting them a place in peace negotiations.

The ELN is holding not only the remainder from La Maria church but 24 people kidnapped in the hijacking of a domestic flight in April.

Five rebels on the flight forced the plane to land on a remote jungle airstrip, where the passengers and crew were abducted.

The latest mass kidnapping was on 7 June, when nine anglers were intercepted during a fishing trip on the Caribbean coast by ELN guerrillas in speedboats.