The fire started at a Chemie-Pack chemical plant in the Moerdijk industrial zone, about 40 km (25 miles) south of Rotterdam, on Wednesday afternoon. The cause of the blaze was unknown and police said there were no reports of any casualties.

However, shipping traffic at the Hollands Diep river, close to the Moerdijk area, was halted, a spokesman for the Dutch ministry of security and justice said.

A spokesman for Rotterdam port, Europe’s biggest, said the impact on traffic between Rotterdam and Antwerp was limited.

The petrochemical complexes of Antwerp and Rotterdam are linked by pipeline and an inland waterway. Rotterdam supplies raw materials for Antwerp’s petrochemical industry.

A spokesman for Royal Dutch Shell said the company’s refinery, located two km from the burning chemical plant, was unaffected and that the wind was blowing smoke in the opposite direction from the refinery.

The fire later expanded to an adjacent factory of Finnish engineering firm Wartsila but there was no danger to the Shell refinery, a police spokesman said.

Wartsila has a logistics centre in the area, according to its website.

Several big explosions took place at the industrial zone with flames more than 10 metres high, television footage from the scene showed.

There was no danger to health from the smoke in the area although the smoke did contain toxic material, the police spokesman said.

People in the area were advised to stay indoors and shut their windows, the spokesman for the ministry of security and justice said.