Nine border guards have been killed after the Taliban stormed a police checkpoint in a north-western province of Afghanistan.

The checkpoint in Badghis province, one of the most dangerous in Afghanistan, came under attack and the guards were killed inside before the insurgents planted mines around the site.

In a gun battle that followed the checkpoint attack, four Taliban insurgents were killed and eight wounded.

The attack came just hours after the Taliban announced their spring offensive in Afghanistan, saying in a statement to media that it will begin tomorrow.

This fighting season will be the first time the insurgents' annual campaign against the Afghan government has taken place without Nato troops on the battlefield.

Foreign combat forces withdrew from Afghanistan at the end of last year, leaving international troops behind to monitor and instruct Afghan forces in the war against the insurgency.