Ljubljana - The death toll of the powerful explosion that ripped through the Melamin chemical plant in Kočevje, south Slovenia, on 12 May has increased to seven after a second of the two severely injured workers died in hospital on Monday, nearly three weeks after Slovenia's deadliest industrial accident.

The latest death was announced by UKC Ljubljana hospital where the worker had been treated for severe burns.

Five of the casualties were killed on the spot and six were injured, two of them severely. One of the severely injured died a week after the accident and the second one today.

Two Bosnian citizens and one Macedonian citizen are believed to have been among those killed in the accident.

The exact cause of the accident has not been determined yet but it was blamed on a human error.