United Kingdom-based providers of voice over internet protocol (VoIP) services were hit by a series of cyberattacks in recent weeks, according to an industry body. An overall threat has been made to the entire industry, Comms Council UK said. Regulatory and competition authority Ofcom said it was aware of the situation. Distributed denial of service (DDoS) attacks flood a website or online service with internet traffic to disrupt services.

The DDoS attacks were meant to extort the companies, according to BBC News.

Sinclair Group cyberattack: All you need to know

VoIP providers offer internet-based calls to businesses and public services, including the police and National Health Service (NHS).

In a statement, Comms Council UK said that the DDoS attacks on VoIP firms during the past four weeks “appear to be part of a co-ordinated extortion-focused international campaign by professional cyber-criminals.”

The body said it was liaising with the UK government, Ofcom and the National Cyber Security Centre.

A Comms Council UK spokesman told the BBC it was not clear how many firms had been affected, but the scale of the attacks was “unprecedented”.

“We have never seen anything like it since we were established back in 2004,” he said.

Sinclair Group cyberattack: All you need to know

“Ransom threats have been made to numerous providers and an overall threat has been made to the entire industry.

“The attackers have started down that path, with attacks under way.”

An Ofcom spokesman said: “We’re aware that some networks have been experiencing problems recently.

“We are in contact with them to establish the scale and cause of the problem, and also liaising closely with the UK Government and National Cyber Security Centre.”

US State Department hit by cyberattack recently: Reports

Experts said DDoS was a bit of a surprise as an attack method.

“Ransomware is more usual for criminals extorting money at present,” BBC quoted cyber-security expert Alan Woodward from the University of Surrey. The NCSC said it was aware of the DDoS attacks and was working with its partners to support affected companies.