After raging for six hours and threatening a large area, a major fire at the Cité des Sciences in Paris, one of Europe's biggest science museums, has been brought under control.

Early on Thursday, as 120 firefighters spent six hours tackling the blaze, a massive plume of black smoke could be seen over a large area in northern Paris. The cause of the fire is still unclear and under investigation; however, the fire alarms at the sprawling site had been switched off because of building work.

Two firefighters were slightly injured while tackling the blaze in a section of Cité des Sciences that is still under construction. One of the firefighters had to be hospitalized for his injuries and extreme heat exposure, according to reports. The other firefighter suffers from smoke inhalation. The blazing flames have damaged multiple levels of the main science museum in Paris.

According to reports, the blaze broke out overnight in the under construction section of the Cité des Sciences. Commander Gabriel Plus said that the cause of the fire is still unclear at the moment. The fire was difficult to contain, and it raged for several hours, prompting concerns that the museum's IMax movie theater and the adjacent exhibit halls could also catch fire. Fortunately, this didn't happen and by midmorning, more than 100 firefighters called on the site were able to bring the blaze under control, according to Plus.

The authorities announced that the museum will stay closed on Thursday. Meanwhile, the firefighting teams will keep monitoring for other fire risks. The science museum complex in north-east Paris houses interactive exhibits on geology, light, space, as well as children's exhibits. Millions of people visit the Cité de Science Museum in Paris every year.

Officials declared that the fire and smoke affected around 10,000 sq m at the Parc de la Villette site. A spokesman announced that several levels of one of the museum's four horizontal cube structures were affected by the fire, and the blaze had also spread to the roof.