Police found two sacks full of guns, grenades and bullets left in a deserted area on Kanchanaphisek Road in Bang Bua Thong district of Nonthaburi province late Monday night.
Local police spotted two fertiliser sacks in front of the entrance of Sombat Buri housing estate near a 7-Eleven store about 10pm on June 9.
The sacks were fopund to contain three rifles, 248 bullets, four grenades used with M79 launchers, one M79 grenade launcher barrel, three smoke grenades, four fire bombs and five ammunition magazines.
Police assumed the weapons were dumped ahead of today's deadline of the National Council for Peace and Order for the surrender of illegal weapons.