If you can't trust kidnappers, who can you trust?

BOGOTA (Reuters) - Colombian mobile telephone users are being duped by criminals who pose as phone operators and instruct them to turn off their handsets just long enough to demand ransom from their families.

Colombia, long one of the world's kidnapping capitals, has seen a rash of cases in which mobile phone customers receive messages telling them to turn off their handsets for two hours because their telephones have been cloned, police say.

The criminals then contact family members of the phone user to say that he or she has been taken hostage. Families who have no way of contacting their relative are directed where to drop off ransom money before the two hours are up.

"If you get a call telling you to turn off your handset, contact the authorities," local television channel Caracol told viewers during a Tuesday news program.