DUSHANBE, July 15 (Reuters) - Russian border guards patrolling the border between Afghanistan and ex-Soviet Tajikistan seized a haul of 2,000 kg of raw opium on Sunday, a spokesman for the guards said. The spokesman said a border patrol had come across armed intruders at about 5:30 a.m. and an exchange of shots ensued. The group was dispersed and although the spokesman gave no details on possible casualties among the gunmen he said the site had been covered in blood.

The spokesman said bags containing opium were recovered and would later be destroyed on the border.

Border guards have so far this year recovered some 3,500 kg of drugs along the border.

Russia helps police the border to bolster a shaky peace in Tajikistan, riven by civil war from 1992 to 1997.

Russian President Vladimir Putin has called for joint efforts by former Soviet Central Asian states to defeat drug trafficking and what he calls the threat of subversion entering the area from Afghanistan.