The building was evacuated and moments ago, the suspect has been arrested, according to Sky News.
Twitter users in England followed the drama:
@SkyNews (London, UK) Armed police surround St Helens factory - described as "significant incident" tinyurl.com/aupp35
@davidlrattigan (Liverpool, England) Alfred Knight Factory on Prescot Road, St Helens, near Liverpool: armed police surround building in 'hostage situation': http://is.gd/lUQE
@prestonlife (Preston, England) armed police reported to have surrounded a factory in st helens-20 mins from preston...more details to follow...
@peterlillie (Liverpool, England) what's going on in St Helens? http://news.bbc.co.uk/1/hi/
@alunhill (London, England) the incident centres on Alfred H Knight International Ltd, a business with global interests, that analyses metals and minerals.
@simonpickles (Liverpool, England) Security alert on Prescot Rd st helens all local roads closed avoid the area
@garretkeogh (London, England) St Helen's merseyside incident described as possible hostage situation.
@liverpoolroads (Liverpool, UK) SEVERE A58 Merseyside - Prescot Road closed both ways at the Freckleton Road junction in St Helens, because of a police incident.
