The President of Colombia, Alvaro Uribe, has defended the role of unions after the assassination of another union leader.
Carlos Barrero, who led the hospital workers, was the 42nd trade unionist to be killed in the country this year.
Speaking after Barrero was shot dead in Barranquilla, Mr Uribe called for the police, powers of justice and public to help afford union leaders better protection.
Mr Uribe said unions were moral reference points, which were necessary for the smooth-running of communities, and they should have guarantees and total respect for their rights.
Correspondents say unions in Colombia are often targeted by right-wing paramilitary groups, which accuse them of links with left-wing rebels.
From the newsroom of the BBC World Service