Spanish Prime Minister Pedro Sanchez's office said he was in touch with Catalan authorities, adding that the government was ready to "provide the necessary support due to this serious event, which has caused several injuries and substantial material damage".
A massive explosion at a petrochemical plant in northeast Spain created a giant mushroom cloud and forced officials to issue an emergency alert on Tuesday.
One person died as a outcome of an explosion at a chemical factory in Spain's north-eastern Tarragona province, Spanish media reports.
Local trains between Tarragona and neighbouring Port Aventura were suspended on police orders before later resuming services, the train operator Rodalies said, while the regional transport authority said some roads had been closed.
Since the blast is declared as a chemical accident, the civil protection agency in the country has warned the city of 0.8 million to stay indoors as a measure of precaution.
Buch said the smoke from the resulting fire was not toxic but he also advised residents to remain inside.
Iqoxe CEO Jose Luis Morlanes said the explosion occurred in a 20-ton tank of ethylene oxide in a part of the plant that had not had any problems since it was built in 2017.
Some local residents told Tarragona Radio that the blast could be heard from miles away.
Tarragona is located 70 miles south west of Barcelona, the regional capital of Spain's Catalonia region.
Since 2015, the city has housed a 1200-hectare "chemical hub, " ChemMed, that was described as the largest of its kind in southern Europe. After that blast, which caused no casualties, authorities had to cordon off an area of some 500 metres (550 yards) in radius around the plant.