A fire swept through a garment factory outside Moscow on Tuesday, killing at least 14 Vietnamese migrant workers, Russian emergency officials said.

Firefighters sent to put out the blaze found 14 bodies in the factory in the town of Yegoryevsk, southeast of Moscow, and four victims were hospitalised with burns, the Moscow region emergencies department said.

All those killed were Vietnamese citizens, the Federal Emergency Situations Ministry said. The Interfax news agency said the garment factory was illegal.

Many migrant workers from Asian countries work in Russian factories in cramped conditions that are often at risk from fires. Death rates from fires are far higher in Russia than in Western countries such as Britain and the United States.

A fire in April on Moscow's outskirts killed 17 migrant workers who had been living in makeshift quarters at a market warehouse, most of them from economically struggling former Soviet republics in Central Asia.