Among them was the Barts Health group which manages major central London hospitals including The Royal London and St Bartholomew’s.
Patients requiring emergency treatment across England were diverted away from the hospitals affected and the public was advised to only seek medical care for acute medical conditions.
The National Health Service (NHS) said it was responding to the incidents.
There was no immediate comment from the Health Ministry.
Earlier on Friday, Spain’s government warned that a large number of companies had been attacked by cyber criminals who infected computers with malicious software known as “ransomware” that locks up computers and demands ransoms to restore access.