A huge aquarium in Berlin that was home to around 1,500 exotic fish burst on Friday, spilling 1 million liters (264,172 gallons) of water and debris onto a major road in the busy Mitte district, emergency services said.

Around 100 emergency responders rushed to the site, a leisure complex that houses a Radisson hotel and a museum as well as what Sea Life Berlin said was the world's largest freestanding cylindrical aquarium at 14 meters (46ft) in height.

"It felt like an earthquake" said Naz Masraff, who had been staying at the hotel.

Another hotel guest, Sandra Weeser, spoke of chaos.

"The whole aquarium burst and what’s left is total devastation. Lots of dead fish, debris," she told Reuters.

Two people were injured by splinters of glass, and emergency services asked around 350 hotel guests to pack their belongings and leave amid concerns that there could be structural damage.

Buses were sent to provide shelter for the hotel guests, police said, as outside temperatures in Berlin in the morning hovered around -7 degrees Celsius (19.4°F).

Radisson told its Radisson Rewards loyalty club members in an e-mail that the Radisson Collection Hotel Berlin was closed until further notice.

Search and rescue dogs scoured the ground floor of the building, which was too littered with debris for responders to access, but found no casualties, the Berlin fire brigade said on Twitter.

A spokesperson for the fire brigade told Reuters it was still unclear what had caused the AquaDom aquarium to burst.

Sea Life Berlin said in a statement its team was shocked by the incident and was trying to obtain more information from the owners of the AquaDom about what had caused the incident.

The company, which had offered glass elevator rides through the AquaDom aquarium, said it would also remain closed until further notice.

Neither the fire brigade nor the police commented on the fate of the fish, though police said on Twitter there had been "unbelievable maritime damage."

Emergency services shut a major road next to the complex that leads from Alexanderplatz toward the Brandenburg Gate due to the large volume of water that had flooded out of the building.

The aquarium was last refurbished in 2020, according to the website of the DomAquaree complex. During the upgrading work, all the water was drained from the tank and the fish were moved to aquariums in the basement of the building, where there is a breeding care facility for the fish, it said.

DomAquaree as well as the AquaDom aquarium are owned by a real estate fund managed by Union Investment.