Trains between Tarragona and neighbouring Port Aventura were suspended on police orders, the train operator Rodalies said, while the regional transport authority said some roads had been closed.
Tarragona is located 115 kilometres southwest of Barcelona, the regional capital of Spain's Catalonia region.
An enormous explosion at a petrochemical plant in northeastern Spain has killed one person and injured at least eight others, according to authorities.
A spokesman for Catalonia's rescue services said the fire had been contained, adding that several of the injured had suffered burns.
One of those who died was a worker at the plant.
Two of the injured were in a critical condition, Miquel Buch, from the Catalan regional government, told TV3.
Morlanes said the company was investigating the causes of the explosion but its inspectors could not approach the site while firefighters were still working. Fire chief Albert Ventosa said the blaze was under control.
The blast in the port city of Tarragona sent a column of black smoke into the sky and prompted local authorities to warn people in surrounding areas to stay inside as a precaution.
The chemical facility, which produces ethylene oxide and glycol, erupted into flame following a massive explosion on Tuesday evening.
La Vanguardia newspaper said on its website that the person died after a building collapsed as a effect of the shockwave generated by the explosion on Tuesday while others have been injured. I went to the door and left right away, " she said. "I thought I was going to have a heart attack".
Since 2015, the city has housed a 1,200-hectare (2,965-acre) "chemical hub", ChemMed, that was described as the largest of its kind in southern Europe.