More than 850 migrants working in Qatar have reportedly died in the past three years as the Gulf state readies for the 2022 World Cup and faces mounting pressure over alleged human rights abuses against migrant workers, according to numbers from a Nepalese human rights organization and the Indian embassy in Doha.

In two separate reports Saturday and Monday, Agence France-Presse and The Guardian newspaper said that more than 450 Indian migrants died in Qatar over the past two years and at least 400 Nepalese workers lost their lives there since December 2010, when the country won its bid with soccer’s international governing body FIFA to host the 2022 championship.

The Indian embassy in Qatar told AFP that on average about 20 Indian migrants died per month since 2012, peaking at 27 in August last year. There were 237 fatalities in 2012 and another 218 in 2013 up to Dec. 5, the news agency said.

The Qatar National Human Rights Committee said Tuesday that the death of over 450 Indian workers in almost two years in the country hosting the 2022 World Cup was "normal" given the size of the community.

Estimated at around 500,000, "Indians make up the largest community in Qatar,” Committee head Ali bin Sumaikh al-Marri said. So, "If we look at the numbers of Qataris who died ... of natural causes ... over the past two years, we see that numbers of deaths among the Indian community are normal," Marri told AFP.

He demanded clarifications on the circumstances of the reported deaths, insisting that there is a "campaign against Qatar."

The Indian embassy did not give details about the circumstances of the deaths or where they occurred. It also declined to hand over any correspondence between the embassy and the Indian government regarding the treatment of its nationals.

The International Trade Union Confederation, an organization facilitating cooperation between trade unions worldwide, said the data showed an “exceptionally high mortality rate.”

In a separate investigative report, The Guardian said that 400 Nepalese migrants had died on building sites in Qatar since 2010 as the country prepares for the World Cup. In September, the newspaper reported at least 4,000 workers’ lives are at risk under current working conditions. Human rights organization Pravasi Nepali Co-ordination Committee is reported to release more details this week.

Last month, an official at the Nepalese embassy in Doha told AFP that 191 deaths had been registered in 2013, many of them from "unnatural" heart failure, compared with 169 the year before.

The Qatar Ministry of Labor told the Guardian, “With specific regard to these new figures, we were aware that local media had previously reported some of these headline numbers, and we are clarifying them. Clearly any one death in Qatar or anywhere else is one death too many – for the workers, for their families, but also for Qataris who welcome guest workers to our country to perform valuable jobs.”

“We are working to understand the cause of these deaths – as these statistics could include a wide range of circumstances including natural causes, and road safety incidents, as well as a smaller number of workplace incidents.”

Qatar's human rights record is under scrutiny as it cranks up construction work – most of which will be done by migrant workers from South Asia – ahead of the massive international sporting event.

Amnesty International said in November that workers were being treated like "animals." The organization urged FIFA to press Qatar to improve conditions for foreign laborers.

FIFA executive committee member Theo Zwanziger said Thursday at a hearing of the European Parliament that the World Cup could help improve the country's "appalling" human rights record by inviting closer scrutiny. FIFA did not respond to Al Jazeera’s request for comment before the publication of this article.

On Feb. 11, the Gulf state issued new guidelines in a charter aimed at protecting expatriate workers, suggesting they should be paid properly and promptly, and should be adequately housed. The Qatar government also commissioned law firm DLA Piper to prepare a report on migrant labor concerns in the country.

“Where any liability is found to rest with employers, the ministry … and Qatari law authorities will pursue these cases through the relevant legal channels. We have increased the number of trained labor inspectors by 25 percent and continue to hire new inspectors, with over 11,500 random spot-checks of workplaces carried out in the past three months.”

Sharan Burrow, the secretary-general of the ITUC, dismissed the labor charter because the guidelines are not legally binding.

"They are window dressing. We have seen it before. And it just seems like this is a country that wants to treat workers as less than human,” she told Euronews.

The embassy in Qatar says that the exact number of Indians in Qatar is unknown, but it was estimated at the end of 2012 to be nearly 500,000, about 26 percent of Qatar's total population. Around 400,000 Nepalese work in the country – about 20 percent of the country's 2 million population.

Al Jazeera and wire services