Four killed in Colombia bombs

The authorities in Colombia say four people have been killed and more than 30 injured, in two separate bomb attacks in different parts of the country.

They blame the main rebel group, the Revolutionary Armed Forces of Colombia (FARC) for the bombings.

Two of those killed were police officers.

They died when a car bomb exploded in the town of Arauca, near the border with Venezuela.

The device went off shortly before a visit to Arauca by Colombia's president, Alvaro Uribe.

In the northern department of Sucre, two marines were killed when a bomb exploded while they were out on patrol.

Meanwhile, more than 20 people were injured when a device went off in the Caribbean port city of Barranquilla.

From the newsroom of the BBC World Service