Cause of US factory blast 'unclear'

The North Carolina plant is still smouldering

Investigators are interviewing workers at a chemical plant in the United States to determine the cause of an explosion which killed three people and injured 37.

The blast and fire which followed destroyed the West Pharmaceuticals factory, in Kinston, North Carolina, on Wednesday afternoon.

The cause of the explosion is still unclear as the plant keeps little volatile material on site, a company representative said on Thursday.

Up to 150 workers were believed to have been inside the factory which produces syringes and other plastic medical supplies at the time of the explosion.

Investigators are interviewing employees

Some of the injured are still in danger with severe burns on up to 70% of their bodies.

Other survivors suffered broken bones and one person's arm was blown off.

'Missing'

One employee was unaccounted for midday on Thursday.

"It was terrible. I was just praying to get out," factory worker Charles Morris told the Kinston Free Press.

"It went black and everything started falling," Jerry Nethercutt told the newspaper.

According to the Occupational Safety and Health Administration, the plant was inspected in October and fined for safety violations.