NEW ORLEANS (REUTERS) - An explosion at a nitrogen plant in Donaldsonville, Louisiana, killed at least one worker and injured seven others on Friday, authorities said, one day after a deadly blast at another chemical plant about 16km away.

The blast hit the CFI Industries plant in Donaldsonville, a small port city on the Mississippi River about 100km north-west of New Orleans, after a nitrogen vessel ruptured, the company said in a statement.

One person died at the scene. Seven people had injuries ranging "from minor to severe" and were transported to several hospitals, Louisiana State Police trooper Jared Sandifer said.

"Workers were filling some type of vessel using nitrogen. It was overpressurised, causing it to rupture, causing the injuries and fatality," Mr Sandifer said. "Because it was nitrogen, there was no flame, just a rupture, like a balloon popping."

The CF Industries plant produces and ships about 5 million tons of ammonia and other nitrogen fertilisers annually for agricultural and industrial uses, according to the company website. The plant was built in the 1960s.

The blast followed the rupture of a "inert vessel" while unloading nitrogen in an area of the plant that was closed for maintenance, the company said in a statement.

CF Industries said there was no fire or chemical release and the incident posed no threat or hazard to the community.

"An investigation into the root cause of the incident is under way," the company said. "We are deeply saddened by the loss of one of our employees."

The explosion in Donaldsonville, a town of about 8,000 residents, came a day after a blast at a Williams Olefins petrochemical plant about 16km north in Geismar that has left two people dead and injured more than 100.

The Geismar blast sent a huge fireball and column of smoke over the plant along the Mississippi River.

A fire and massive blast at a nitrate fertiliser plant in West, Texas, in April, killed 14 people and injured more than 200, focusing attention on the hazards of handling chemicals.

That explosion flatted an apartment building, nursing home and school in West. Most of those killed were firefighters and paramedics responding to a blaze that preceded the explosion.