The Colombian authorities are trying to restore electrical power to large parts of the country after a series of attacks on pylons overnight.

The worst-hit area was the province of Antioquia and its main city, Medellin.

The government is blaming the sabotage on the country's second biggest guerrilla group, the National Liberation Army, or ELN.

Rebel groups destroyed more than two-hundred and fifty electricy pylons last year, forcing the introduction of electricity rationing.

From the newsroom of the BBC World Service