Humberside Police have pledged to take action against anyone posting social media comments inciting violence or racial hatred after a soldier was murdered in south-east London.
Drummer Lee Rigby, 25, was murdered in a suspected terror attack in Woolwich on Wednesday.
A Humberside Police spokesman said: "We are aware of a number of messages that have been posted on social networking sites by a small minority of individuals.
"These messages appear to be an attempt to incite trouble by posting messages inviting people to assemble and cause trouble at particular locations.
"We are monitoring these sites in Humberside and we will take action against those intent on attempting to incite violence or post messages of a racial nature."
Officers have also reassured the community that they are ready to tackle any disorder.
More news on hulldailymail.co.ukBookmark hulldailymail.co.uk/news for the best breaking news and exclusive local content.