An "air raid" siren was heard across parts of Merseyside this morning.
A number of people said they were 'alarmed' by the siren as they did not know where it came from.
Riley Taylor posted a video in a local Facebook group this morning at around 10.45am.
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In a message, he told the ECHO : "It really scared me, to be honest, I thought we were about to go into conflict and lots of people stopped what they were doing."
He posted in a local group: "Anyone else hear that siren in Birkenhead/Rock Ferry just then?"
A number of people speculated that it could be from Cammell Laird in Birkenhead, although the company denies the siren came from them.
One person described it as sounding like an "air raid" alarm.
A spokesperson for Cammell Laird told the ECHO: "I can confirm that the siren that went off this morning at 10am did not originate from the Cammell Laird site."
Merseyside Police also confirmed it had received no reports in relation to the siren.
A leaflet previously handed out to residents in Wirral from Tranmere Oil Terminal confirms that they conduct siren tests on the first Wednesday of every month.
Despite the company not directly confirming the siren this morning came from the oil terminal, it is believed that it is the cause of the eerie sound that beckoned across parts of Merseyside.
The siren is used to give a warning to people about a major incident that could effect the public.
The leaflet said: "A siren has been installed for the specific purpose of giving warning of a major incident having potentially serious effects outside the Tranmere Oil Terminal site.
"In the extremely unlikely event, such an incident should occur, this siren would be sounded, giving a variable pitch sound - sometimes referred to as an air raid warning. Siren testing takes place at 10.00am on the first Wednesday of every month.
"Please ensure you listen to the test and familiarise yourself with the siren tone."
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