At least 49 people, all Indian nationals, have been killed in a fire which swept through a building housing foreign workers in Kuwait.

More than 50 others were injured in the blaze, which broke out in the six-storey building south of Kuwait City at dawn on Monday.

Flames engulfed the lower floors as black smoke poured out of the upper-storey windows, unverified images posted on social media showed.

The interior ministry revised the death toll up to 49 from 35 after forensic teams scoured the building.

“The number of deaths as a result of the fire in the workers’ building … has risen to 49,” the ministry said.

The official Kuwait News Agency quoted the health minister Ahmad al-Awadhi as saying hospitals had received 56 people injured in the fire in the Mangaf area, which is heavily populated with migrant labourers.

The building housed 196 workers, according to information given to the interior minister by their employer.

Oil-rich Kuwait has large numbers of foreign workers, many of them from south and south-east Asia, and mostly working in construction or service industries.

A source in the fire department said the victims suffocated from rising smoke after the fire started at the building’s base.

A foreign ministry statement said later the “tragic” fire had “claimed the lives of 49 citizens of the Indian community residing in the State of Kuwait”.