Police in the northern city of Hai Phong Tuesday arrested a man accused of producing weapons and selling them to gangsters.
More than 40 police officers stormed into the workshop where Duong Minh Nhat, 38, and his wife Tran Thi Hong Van, 42, were caught red-handed manufacturing weapons.
They arrested the couple and seized five finished pen guns from the workshop, which they said is the largest one in the city.
The police then searched Nhat's house and seized some guns, 45 bullets and equipment used to produce weaponry.
They said Nhat used to be a mechanic and possessed the skills to make a variety of guns, which he sold mostly to gangsters.
He and his wife, both drug addicts, spent the money they earned to feed their drug habits, police said.
Further investigations are ongoing.
According to police, Nhat has two previous convictions. In 2000, he was sentenced to three years in jail for vandalizing telecom devices.
In 2002, he was sentenced to 14 and one half years in prison under the same charge.
In 2008, Nhat was released on medical parole after testing positive for HIV and had been free until his arrest on Tuesday.