BOGOTA, Colombia (AP) _ Three more hostages were freed Thursday by guerrillas who seized an Avianca domestic flight earlier this week.

The government, meanwhile, accused two top leaders of Colombia's No. 2 rebel group as being the masterminds behind ``the terrorist act.''

The freed hostages, two women and a man all said to be in poor health, were released to the International Red Cross. They were handed over in San Pablo, a town in the state of Bolivar that is 180 miles north of Bogota and not far from where the plane was forced down on Monday.

Their liberation brought to nine the number of passengers freed by rebels who commandeered the commercial flight from the northeastern city of Bucaramanga to Bogota, redirected it to a grassy, jungle landing strip and hauled its occupants deep into rebel-held territory.

Thirty-two passengers and crew remain in rebel hands.

In a statement Thursday, the government accused Pablo Beltran and Oscar Santos, members of the five-man ruling junta of the rebel National Liberation Army, or ELN, of ordering the hijacking of the twin-engine Fokker 50 turboprop.

President Andres Pastrana had already accused the 5,000-member guerrilla group in the crime. By naming high-ranking ELN commanders, the government may be trying to prompt a rebel claim of responsibility in the brazen act.

So far, the ELN has neither acknowledged nor offered explanations as to why it seized the plane and its occupants.

Political analysts say the rebels may be trying to force the government to take it more seriously in fledgling peace talks. The ELN may also be seeking a ransom, the prime motive for hundreds of kidnappings it carries out each year.

Also under investigation in the crime are personnel from Bucaramanga's Palonegro airport, where the five well-dressed guerrilla hijackers boarded the plane carrying briefcases. The hijackers ``made a joke of security controls'' in bringing arms onto the plane, the government said.

One of the six hostages freed on Tuesday said airport workers passed carry-on luggage through X-ray machines but didn't bother to frisk the passengers.