Pubs in a seaside town closed early following reports of "low-level disorder", police said.
Several venues in Cromer, Norfolk, said they had decided not to open on Saturday, with residents describing the town as in "lockdown" on social media.
Norman Lamb, Liberal Democrat MP for North Norfolk, tweeted: "Very concerned by what I've read online tonight. Of course happy to support people in Cromer in any way I can."
Norfolk Police said it had increased resources in the town but dismissed reports that someone had been stabbed.
The force said: "We have additional resources in Cromer tonight following reports of low-level disorder earlier today.
"We are aware licensees of local pubs have taken the decision to close this evening and we will have additional officers on patrol to provide reassurance to the local community.
"We are also aware of mentions on social media relating to a stabbing in the town tonight - we can confirm no such incident has been reported to us."
Cromer Pier said it had closed its Theatre Bar on the advice of police.
A statement on the venue's Facebook page said: "On advice from the police the Theatre Bar is closed to the public this evening as are all the other public houses in Cromer.
"Apologies for any inconvenience whilst we support our local police in bringing a difficult situation in the town under control."
The Wellington pub tweeted: "We will not be opening our doors tomorrow! Hopefully normal service will resume on Monday!"
The Red Lion Hotel also wrote on Twitter: "Please be aware the Red Lion is closing early this evening due to local events in the past 24 hours."