Tajik officials say border guards have killed eight Afghan drug smugglers trying to sneak into the country.

The officials say troops patrolling the southern border spotted a group of 12 people crossing a river dividing the two countries.

They say gunfire broke out and eight drug carriers were killed, while the remaining four managed to return to Afghan territory.

A large quantity of drugs and weapons was later found at the site of the clash.

Tajikistan shares a 1,300-kilometer border with Afghanistan. The Central Asian country has become one of the main routes for illegal drugs entering Russia and western Europe from Afghanistan — the world's largest producer of opium.