Two people died and 56 people were injured after two explosions rocked an unlicensed liquefied petroleum gas filling station just north of Romania's capital Bucharest late on Saturday, officials said.

Most of the injured were firefighters who rushed to the station to extinguish the blaze from the first explosion before the second occurred.

The two people who died were a couple, emergency department head Raed Arafat told reporters on Sunday.

The man suffered a heart attack, while the woman died after sustaining severe burns, he added.

Among the injured -- some with severe burns -- were 39 firefighters, two police officers and two gendarmes, according to Arafat.

"Overnight we transferred two firefighters and two civilians abroad (for treatment) and more will follow," he said in a statement.

The four were taken to Italy or Belgium, according to the defence ministry.

Romania has requested assistance through the EU Civil Protection Mechanism to treat 18 burn patients, European Commissioner for Crisis Management Janez Lenarcic said on X, formerly known as Twitter.

Austria, Germany and Norway offered help, Lenarcic said.

It was not immediately clear what caused the blasts in Crevedia commune, and prosecutors have opened an inquiry.

"We know that the station was no longer working, so it clearly didn't have a permit to function," Arafat said.

The fire also forced the evacuation of people within a 700-metre (770 yards) radius.

"I'm profoundly saddened that the explosions in Crevedia resulted in victims," President Klaus Iohannis wrote on Facebook, calling it a "tragedy".

Anger has flared repeatedly in the EU member state over a lack of official oversight to ensure compliance with safety regulations.

In 2015, a blaze ripped through a Bucharest nightclub after fireworks were let off, killing 64 people.