A man arrested on suspicion of threats to kill had to be detained for a second time on a dual carriageway while on the way to custody.

Police officers were forced to pull up on the A405 in Garston yesterday afternoon.

A Hertfordshire Constabulary spokesperson said: "Police were called to Callowland Recreation Ground, Watford, on Sunday, at just after 12.30pm, to reports of an altercation.

"Officers attended and on arrival found a man acting aggressively.

"A 25-year-old man was arrested on suspicion of two public order offences, assault on police and threats to kill.

"On route to custody it was necessary to put further measures in place to ensure the man’s safety following concerns for his welfare.

"He has been released under investigation while enquiries continue."