BANGKOK, April 5 (Xinhua) -- A Thai police unit clashed with an unknown group of armed men on the border with Laos and seized more than 41,000 tablets of methamphetamine on Thursday, police said.

Policemen attached to Company 246 of Thailand's Border Patrol Police exchanged gunfires with several armed men who had crossed Hueang River from Laos to Thai territory in Tha Li district of Loei province, about 540 km northeast of Bangkok early Thursday.

The unidentified men were allegedly trafficking 41,386 pills and a kg of "ice" crystals of methamphetamine contained in fertilizer bags across the river which has run dry along the Thai-Lao border, the police said.

The suspected drug traffickers managed to slip back in the dark to the Lao side, leaving behind the drugs, following the 20-minute clash in which no casualties were reported.?