They are calling it the "crossed legs" strike.

Fretting over crime and violence, girlfriends and wives of gang members in the Colombian city of Pereira have called a ban on sex to persuade their menfolk to give up the gun.

After meeting with the mayor's office to discuss a disarmament program, a group of women decided to deny their partners their conjugal rights and recorded a song for local radio to urge others to follow their example.

"We met with the wives and girlfriends of gang members and they were worried some were not handing over their guns and that is where they came up with the idea of a vigil or a sex strike," mayor's office representative Julio Cesar Gomez said.

"The message they are giving them is disarm or if not then they will decide how, when, where and at what time," he said.

Gomez said the city, in Colombia's coffee-growing region, reported 480 killings last year.

Crime and violence have dropped in Colombia since 2002 when President Alvaro Uribe was first elected promising to crackdown on left-wing rebels and the illegal militia groups who formed to counter them.

But cocaine-trafficking gangs and armed groups still roam parts of Colombia and murder and kidnappings remain a problem despite the fall in crime statistics.