MEXICO CITY (Reuters) - Four more people have been found dead after last week's explosion at a petrochemical plant in south-eastern Mexico, raising the death toll to 32, state oil giant Pemex and Mexican plastic pipe maker Mexichem said in a joint statement on Sunday (April 24).

The vinyl petrochemical plant in the Gulf coast state of Veracruz is a joint venture between Pemex's petrochemical unit and majority owner Mexichem.

Pemex's chief executive has said that last week's blast was caused by a leak but he did not how the leak had happened exactly.

It was the latest in a series of fatal accidents at the company.