At least 17 workers died in a horrific fire in the southwest of Moscow early Tuesday morning. The fire broke out around 5 a.m. in a metal shed at the Kachalovsky market, where the young men worked, and lasted more than two hours. The workers, the youngest of whom was just 20 and the oldest 39, were burnt alive. They appear to have been undocumented migrant workers from the Central Asian republics of Uzbekistan and Tajikistan.

The total number of dead might still increase. Only 11 of the victims have been identified so far due to the condition of the corpses. Four of the victims bore the same family name and seem to have been brothers from Uzbekistan.

The fire was the worst such incident in Russia since 2007, when 11 people were killed in a nightclub blaze.

The police suggest the fire was caused by an electrical heater that malfunctioned. The shed had no smoke alarm. Police indicated it was impossible for the workers to escape through the door, although they did not explain why. The fire brigade had to tear down the wall of the building to extinguish the fire. The blaze reportedly spread to an area of 50 square meters.

The head of the Ministry of Emergency Situations, Sergey Shoigu, who is leading the investigation, said that “the object [i.e., the shed] was absolutely unfit for shelter”. An unnamed offical told the news agency Interfax that the workers “lived in a metal annex that was equipped with a space heater … They slept in frighteningly tight conditions, on hard bunks that were then stacked on top of one another”.

Sedrak Stepanyan, the owner of Albaset, the company that rented and used the structure, and Vladimir Lykov, the owner of the building and head of the Start-2 construction company, were arrested by police Tuesday on charges of having violated fire safety rules and involuntary homocide. The maximum sentence for these charges is seven years in prison. The latest fire inspection at the market is said to have taken place as recently as February 27.

The fire is likely the result of criminal neglect by the workers’ employer. Such conditions and incidents, however, are not unusual in Russia. The country is host to the world’s second largest number of migrants, the vast bulk of whom originate from former Soviet republics, particularly those in the Caucasus and Central Asia, and who are forced to live and work under slave-like conditions.

Tajikistan and Uzbekistan, where the deceased workers apparently originated from, are among the poorest countries in Asia. The dissolution of the Soviet Union led to a dramatic collapse of the countries’ economies and a rapid increase in poverty. In Tajikistan, the economy shrank by 30 percent in the 1990s, and 80 percent of the population now lives beneath the official poverty line. In 2010, 46.3 percent of the population in Uzbekistan subsisted on a maximum $1.25 a day, and 76.7 percent on not more than $2, according to the Oxford Poverty and Human Development Initiative.

With the countries’ economies devastated, many young men are now working abroad, mostly in Russia. An estimated 700,000 Tajiks, a tenth of the country’s population, are currently working in Russia. A signficant number of families, particularly in the countryside, are entirely dependent on the money earned by familiy members abroad. Remittances from migrant workers constituted 42 percent of Tajikistan’s GDP in 2008.

Estimates of the number of undocumented migrant workers in Russia range from 4 to 9 million. The majority of them are employed as unskilled workers in construction, agriculture, transport and manufacturing. Earning poverty wages and deprived of social, working and legal rights, these workers are left at the mercy of their employers. They are forced to live under degrading and inhuman conditions, without access to adequate food, utilities, health care or other services. Often they don’t receive written contracts and their payment is frequently withhold. The global economic crisis, which has hit Russia hard, has led to a further deterioration in the conditions of this most vulnerable section of the working class.

Accidents at worksites occur frequently. Given state protection, the responsible employers, who operate in the shadow economy with the workers’ identities often remaining unknown, are hardly ever held accountable.

Moreover, in a climate of rising national tensions, deliberately ratcheted up by the Kremlin, migrant workers often fall prey to violent attacks by nationalists and police.

The chauvinist and racist campaigns by the Kremlin, mainly aimed at diverting attention from burning social problems, abet the flagrant exploitation of foreign workers. Thus, for example, around 300 Tajik workers were deported in November 2011 during the election campaign. Prime Minister Vladimir Putin, elected Russian president on March 4, called for tighter control of migrant workers in an article “On the National Question” in January 2012.