Vietnamese police have arrested 16 gang members and rescued 51 dogs as part of an investigation into the theft of thousands of dogs in the north of the country.

Thousands of dogs have been stolen since the beginning of the year in the province of Thanh Hoa, 150 kilometers south of Hanoi, according to a local police report.

In total, authorities questioned more than 40 suspects, linked to the gang, and arrested 16.

"This gang has been active for a long time," said one local policeman, who asked not to be named.

The gang reportedly took motorcycles in residential areas late at night to steal dogs, using stun guns, bait and bags.

Earlier this week, food safety officials in Ho Chi Minh City urged local residents to stop eating dog meat in a bid to improve the national image.

Dog meat is a delicacy for many in Vietnam.