One policeman has been killed and seven others
injured in an attack on a police checkpoint north
of the capital Bogota.
The officer was shot dead by two assailants on
motorcycles while he was on duty in the city's
northern outskirts, police said.
The attackers planted explosives on the body and
set them off when other officers came to
investigate, they say.
Foreign Minister Luis Carlos Villegas said the ELN
rebel group is likely to have carried out the
attack.
"The leading theory is that this incident is the
heinous and irresponsible work of the National
Liberation Army (ELN) to terrorise the civilian
population," Mr Villegas told Caracol radio.
Power stations have in the past been attacked by
the ELN, Colombia's second-largest rebel group.
But the police said the attack could also be part
of a plan by criminal gangs to target police
officers.
Attacks on the security forces used to be
relatively common in Colombia, with the ELN and
the larger Farc rebel group both fighting the state,
but they have become rare.
Who are the Farc?
How significant is the ELN?
The Farc signed a peace deal with the
government in November, putting an end to more
than five decades of armed conflict.
The ELN is due to start peace talks with the
government in January but the group has so far
refused to release a former Congressman it is
holding hostage, which the government says is a
prerequisite for the talks.
There are also a number of powerful criminal
gangs operating in Colombia, some of which have
in the past called for their members to kill police
officers.
Officials said the assailants' original target may
have been an electrical substation near the
checkpoint in the sparsely populated area.
