Mobile phone masts have been torched amid theories linking coronavirus to 5G, despite ministers saying there is no credible evidence to back them.
Masts were set alight in Sparkhill, Birmingham, on Thursday and Melling, Merseyside, on Friday.
Trade body Mobile UK said false rumours and theories linking 5G and coronavirus were “concerning”.
The government said “there is absolutely no credible evidence of a link” between the two.
Posting on Twitter, the Department for Digital, Culture, Media and Sport added it was “aware of inaccurate information being shared online about 5G”.
In Melling, Merseyside Fire and Rescue Service said it extinguished a 5G mast tower fire near the M57 motorway.
There was damage to the mast and control panels, a spokesman said.
West Midlands Fire Service said the fire in Birmingham involved a 70ft tower on a telecommunications site. However, the service said the cause was yet to be identified and could not confirm the mast was 5G.
A West Midlands Police spokesman said: “We’re aware of a fire involving a phone mast, but are awaiting further details on its cause.”
On Friday, Facebook removed a page which showed several videos claiming to show 5G towers on fire and encouraged others to do the same.
In addition to warning on the theories about the safety of 5G technologies, Mobile UK added: “More worryingly some people are also abusing our key workers and making threats to damage infrastructure under the pretence of claims about 5G.
“This is not acceptable and only impacts on our ability as an industry to maintain the resilience and operational capacity of the networks to support mass home working and critical connectivity to the emergency services, vulnerable consumers and hospitals.”
By Leo Kelion, BBC technology desk editor
Conspiracy theories linking 5G signals to the coronavirus pandemic continue to spread despite there being no evidence the mobile phone signals pose a health risk.
Fact-checking charity Full Fact has linked the claims to two flawed theories.
One suggests 5G suppresses the immune system, the other claims the virus is somehow using the network’s radio waves to communicate and pick victims, accelerating its spread.
While 5G uses different radio frequencies to its predecessors, it’s important to recognise that the waveband involved is still “non-ionising”, meaning it lacks enough energy to break apart the DNA in our cells to cause damage