India launched a probe Tuesday after 12 applicants for coveted government jobs died during physical tests for posts as excise officers, with commentators saying it illustrated the scale of the country's unemployment crisis.

The young men were among 500,000 applicants vying for just 583 jobs as constables in the government excise department -- more than 850 people for each post.

India is the fastest-growing major economy, and the fifth largest, but the world's most populous country has a jobs crisis to match.

It has struggled to produce enough full-time and well-paying jobs for millions of people.

Government jobs, even the lowest ones, are highly sought after, with regular reports of candidates taking extreme measures to secure one.

In past recruitment drives, people have run deep into debt to pay bribes to clinch jobs, or paid for leaked papers for highly competitive entrance exams.

In this case, 12 men died in the past two weeks during a series of 10-kilometre (6.2 mile) races in humid conditions in India's eastern Jharkhand state.

Jharkhand state chief minister Hemant Soren called the deaths "heartbreaking", and ordered health experts to examine the "untimely death of these youth, so that such accidents do not happen in future".

State police chief Anurag Gupta confirmed the deaths and said investigations had begun. The recruitment drive has been paused.

Jharkhand has some of India's highest unemployment and poverty rates.

The Times of India newspaper quoted doctors as saying that many candidates had been hospitalised with low blood pressure due to dehydration.

The paper, in its editorial on Tuesday, said the recruitment deaths were "a symptom" of the wider unemployment crisis.

"These aren't competitions," it read. "These are pitched battles for survival –- for a stab at securing livelihoods for a working-age people."