Firefighters were reported to have rescued several people when they were called to the scene at the Butterfly club on the Canary island’s south coast, at 2.30am on Sunday.
A four-metre long section of the ground floor is understood to have collapsed, with debris falling through into the basement.
Two of the 22 injured are thought to be in a serious condition.
The UK Foreign Office has confirmed that “a number of British nationals” were injured.