A police helicopter has crashed in a jungle area of north-west Colombia, killing at least 15 officers.
The policemen were on an operation to try to arrest one of the leaders of the Usuga Clan, a powerful drug-smuggling gang that operates in the area.
An initial police investigation has blamed the loss of the aircraft on technical failure.
The Black Hawk helicopter crashed as it tried to land in a remote mountainous area of Antioquia.
Antioquia is 450km (280 miles) north-west of the capital, Bogota.
Last week, 11 air force personnel died in a helicopter crash near the Colombian Caribbean coast.
Left-wing rebels and criminal gangs, like the Usuga Clan, are known to operate in the Gulf of Uraba region.
The police operation was aimed at arresting Luis Orlando Padierna Pena, known as Inglaterra (England), El Tiempo newspaper reported.
The alleged head of the clan is Dairo Antonio Usuga David, known as Otoniel.
The US has offered a reward of up to $5m for information leading to his arrest.