BANGKOK -- Police in Thailand said they have seized more than a ton of crystal meth and over 10 million methamphetamine tablets in a series of drug raids this month, amid increased production and use of the drugs in Southeast Asia.

Thai authorities often make several large seizures a year of methamphetamine and other drugs, usually arresting low-level traffickers and drivers.

Police said in statements Sunday and Monday that they arrested eight people for trafficking over 5 million methamphetamine pills, 600 kilograms of crystal meth, 15.4 kilograms of heroin and 51 kilograms of ketamine. The drugs were discovered Friday in a pickup truck hidden under fruit baskets and at a trafficker's home.

Police said they seized 459 kilograms of crystal methamphetamine last week that they suspect originated from neighbouring Myanmar. The drugs were found in the back of a pickup truck covered under a large green canvas.

In Chiang Mai province, 563 kilometres north of Bangkok, police said a firefight between officers and drug traffickers broke out last Wednesday night while officers were tracking the traffickers in a forest.

Police said they found the dead body of one drug trafficker Thursday lying next to a pistol, in a case in which they seized around 5 million methamphetamine tablets, around 10 kilograms of crystal meth and 10 kilograms of ketamine, as well as a pistol and a cellphone.

In a separate case also last Wednesday, police arrested six people for trafficking drugs to southern Thailand. Police said they seized 58 kilograms of crystal meth that was found hidden in a secret compartment traffickers had made to store the drugs in a pickup truck.

Police also seized 898,000 methamphetamine tablets on July 1 at a pickup truck that traffickers had abandoned.

Australian police said in June that they seized a record 1.8 tons of methamphetamine at the Melbourne waterfront that was hidden in stereo speakers shipped from Bangkok.

The UN's anti-drug agency said in March that production of methamphetamine is skyrocketing in Southeast Asia, with prices dropping and usage expanding.