British counter-terrorism police are aiding the investigation after a knife attack around a migrant which saw one person killed and another injured on Sunday.

A 44-year-old man has been arrested after police responded to reports of a stabbing at a residential address in Hartlepool, northeast England, discovering one man with knife injuries, and a second man on a nearby street who died at the scene. A police statement said “due to the circumstances”, counter-terror officers have “taken responsibility for leading the investigation”.

Counter-terror police taking over the investigation is a development from previous communications from the force, when they said they were merely being assisted by the specialist officers. Nevertheless,  a terrorist incident has not been declared and officers say they are still working to establish the facts of what happened in the pre-dawn of Sunday morning, including exploring “any potential motivation”.

Cleveland police say they do not believe any further people were involved and there is no other immediate threat to the public.

Broadsheet The Daily Telegraph reports the attack is thought to have started inside a migrant accomodation centre and that the suspect proceeded from that venue to kill outside. Broadcaster Sky reports the remarks of neighbours of the address at the centre of the alleged attack, who said “Everyone here knows there’s asylum seekers living there. There’s always people coming and going there.”

The British government maintains a national terrorism threat level, on a scale from ‘low’ to ‘critical’, rating it presently at ‘substantial’, meaning “an attack is likely”. France has increased its warning level in their own system in the wake of the assasination of a teacher by an “Allahu akbar” shouting knifeman in a terrorist attack on Friday.

This story is developing. More follows