A man and woman were arrested in Hanoi on Thursday for trading in illegal fireworks, VnExpress reported.
Vietnam's government banned firecracker production, trade and use in 1995 after a long history of accidens.
Authorities say that police pulled over Nguyen Cuu Xuan, 48, and seized 16.2 kilograms of firecrackers.
Xuan led the police to Nguyen Thi Tham, 37, who sold the explosives to him for VND3.5 million (US$179).
Search at Tham's house found a further 30 kilograms of firecrackers, 18 kilograms of fireworks, along with hundreds of plastic guns she had imported from China.
The plastic weapons are also illegal in Vietnam, considered as unsafe toy for children.
Every Tet season, Vietnamese porters travel to northern border markets and purchase firecrackers.
The festive explosives remain legal in China, which usually celebrates the New Year around the same time as Vietnam.
This year, the New Lunar Year starts February 3.