2 July 2010 Last updated at 14:36 ET

Seven dead and nine wounded in Colombia shooting

Gunmen have opened fire in a nightclub in Envigado, north-western Colombia, killing at least seven people.

At least nine others were wounded in the attack near Medellin, Colombia's second largest city.

Police said the attackers opened fire indiscriminately with machine-guns before escaping on motorbikes.

Officials suspect the killings were related to a dispute between rival cocaine-trafficking gangs.

Police said that some of the weapons used in the attack were the same make as arms popular with drug-trafficking organizations in Mexico, indicating that they may have been imported, according to Colombia Reports newspaper.

Medellin has seen a surge in drug-related killings in recent months, making it one of the most violent cities in Colombia.

"This indicates that we must all do more, starting with the president, the ministry of defence, the armed forces, justice," he later said in a statement.

"Drug killings are a very, very serious matter that should not be taken in vain."

According to CIA statistics, Colombia is the world's biggest producer of cocaine, although production has consistently dropped, from 600 tonnes in 2007 to 430 tonnes in 2008 and 410 tonnes in 2009.