KUNMING - Drug trafficking in southwest China's Yunnan Province remains a major problem after border police seized nearly five tonnes of narcotics in 2012, provincial border police said Tuesday.

Border police in Yunnan captured 2,820 suspects in 2,458 drug cases, seizing a total of 4.95 tonnes of narcotics last year, up 43 percent compared with 3.45 tonnes in 2011.

The drugs seized by border police accounted for 31 percent of the province's total last year. It was also more than 80 percent of the country's total of narcotics seized by border police.

Narcotics from abroad have been smuggled into Yunnan via multiple channels such as land, water and air transport in addition to postal services in recent years, said a provincial border police officer.

Yunnan, which has a 4,060-km-long border with Myanmar, Laos and Vietnam, suffers from the notorious international drug source of the "Golden Triangle."

In 2011, Yunnan seized 13.6 tonnes of narcotics in total, up 45.3 percent year on year. The drugs included 7.7 tonnes of methamphetamine, commonly known as "ice", and 4.9 tonnes of heroin, which accounted for 60 percent and 70 percent of the country's total respectively.