A reporter accompanying a humanitarian mission on Sunday to release four hostages held by Colombian rebels said the military had interfered with and delayed the handover.

Jorge Enrique Botero said the International Red Cross mission — in a loaned Brazilian military helicopter — has been hounded by military overflights.

"This pursuit was ordered by military commanders," Botero told the Venezuelan television network Telesur by telephone from a jungle clearing. He said he had video recordings to prove his allegations.

Colombian military officials had no immediate comment on the allegations. A spokeswoman said that Defense Minister Juan Manuel Santos had been informed.

Botero said at mid-afternoon the handover of the three police officers and one soldier was nevertheless about to occur. "We're a few meters (yards) from them."

Botero said the group hoped to make it by sundown to the lowland provincial capital of Villavicencio, where reporters and relatives of the hostages had been waiting all day for their arrival.

The four security force members were captured by the Revolutionary Armed Forces of Colombia in 2007. They are among six hostages the FARC said it would free this week. Also due to be released are two politicians who have been held far longer.

Analysts consider the unilateral releases — the guerrillas' first in nearly a year — a goodwill gesture. However, chances for a peace dialogue with Colombia's government remain far off and the alleged military interference Sunday is only apt to complicate matters further.

Also speaking with Telesur was the guerrilla commander in charge of the handover and who identified himself as Jairo Martinez.

Martinez said Colombia's military had killed a rebel in his unit in combat on Sunday morning.