Merseyside Police have arrested a man on suspicion of arson after a fire involving a telephone mast.
The 47-year-old man was arrested on Friday following the fire at the mast on Coopers Lane in Kirkby at 9.45pm on April 5.
Attacks on phone masts across the UK have been reported after conspiracy theories spread on social media claiming coronavirus was linked to the rollout of 5G, despite scientists describing such a theory as "both a physical and biological impossibility".
Chief fire officer of Merseyside Fire and Rescue Service Phil Garrigan said: "Our crews have attended an increased number of arson attacks on phone masts in recent weeks.
"This highly irresponsible behaviour is putting lives at risk, preventing ill people from being able to call for help and robbing others of their only contact with their families.
"We will continue to work with our police colleagues to ensure these idiotic actions are investigated and those responsible are held to account."
Police said the man, from Kirkby, was being questioned and a joint investigation with the fire service was under way.
Detective Inspector Steve Ball said: "Incidents of this nature are not victimless crimes and can have serious consequences.
"More than ever, all members of the public are dependent on technology, including their mobile phones, to keep in touch with loved ones.
"People may also need their phone lines to contact the emergency services when they are in need, and stupidity like this could put someone's life at risk."
A spokesman from Vodafone said: "We are extremely grateful to Merseyside Police for the swift arrest in relation to an attack on one of our masts. With this arrest, we hope that others realise that this is a serious criminal offence and stop.
"The damage goes far wider than knocking out a mast. It prevents people from calling their loved ones and disrupts essential connectivity for the NHS and the emergency services at a time of national crisis."
Anyone with information is asked to DM @MerPolCC on Twitter or contact CrimestoppersUK anonymously on 0800 555 111.