Counter terrorism police have taken over the investigation into an attack in Hartlepool which left one man dead and another injured.
A 44-year-old man has been arrested on suspicion of murder and attempted murder following the incident, which took place in the early hours of Sunday morning.
Officers have been granted a further 12 hours to question him.
Cleveland Police said earlier it was being “supported” by Counter Terrorism Policing North East, but confirmed on Monday afternoon that the specialist force had now taken over lead responsibility for the probe.
“Extensive enquiries continue to establish the full circumstances and explore any potential motivation,” Cleveland Police said.
“We are keeping an open mind as we investigate to establish the facts, as we would normally do in these types of circumstances.”
The incident started in Wharton Street at 5.17am on Sunday.
Police were called to a property and found an injured man who suffered non-life-threatening injuries. He remains in hospital.
A second man was found on nearby Tees Street, and he died at the scene.
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The head of Counter Terrorism Policing North East, Detective Chief Superintendent James Dunkerley, said: “Although our inquiries are still at a very early stage, the circumstances surrounding this incident have resulted in Counter-Terrorism Policing taking the lead for this investigation.
“From the inquiries undertaken so far, there is no evidence to suggest that there was any other person involved in the attack, and, at this time, we are not looking for anyone else in relation to the incident.
“Our deepest sympathies go out to the family and friends of the man killed yesterday, and our thoughts are with the man who remains in hospital.”
Cleveland Police Deputy Chief Constable Victoria Fuller said its officers were still helping with the investigation.
She said “incidents of this nature are very rare” but added that extra patrols were taking place in the community to try and reassurance residents.