The Colombian President, Ernesto Samper, has said a special police force is being set up immediately in the north-east of the country in an attempt to control an escalation in killings and kidnappings.

The president was speaking during a visit to the city of Barrancabermeja, where two weeks ago eleven people were killed and another thirty-four taken hostage.

A right-wing paramilitary group said it carried out the attack.

The BBC South America correspondent ,who's in Colombia, says paramilitaries and left-wing guerrillas are active in the area.

Our correspondent adds that worries over security have increased nationwide as Colombia prepares for presidential elections this weekend.