Officers from Humberside Police were called to reports of a disturbance on Cheadle Close in Hull at approximately 10am on Saturday 13 June.
A man was believed to have been in the street carrying a knife and shouting.
Officers attended and a 31 year-old local man was arrested on suspicion of affray and possession of an offensive weapon. He was taken to a local police station for questioning.
Following enquiries, on Saturday night the man was further arrested for offences under Section 41 of the Terrorism Act. He remains in custody at this time. A warrant of further detention was granted on Sunday afternoon for a further seven days.
Counter Terrorism Policing North East are leading the investigation with full support from Humberside Police.
Chief Superintendent Scott Young from Humberside Police said: “We appreciate that this may be a concerning time for the local community.
“We do believe this to be an isolated incident with no wider risk to the public.
“We would like to thank you for your support and patience at this time.”
Humberside Police constantly work to ensure our communities are safe from the evolving threat posed by terrorists but we can’t do it alone. Partner agencies and communities play a crucial role in defeating terrorists and your support and vigilance is key.
If you think you have seen something suspicious that may be linked to terrorist activity have the confidence to share those concerns. It may be unusual behaviour in a particular place or at a particular time of day – don’t rely on others.
If you suspect it, report it by visiting www.gov.uk/ACT or by telephoning 0800 789 321.