Chapel Street has been closed off following reports of a man with a knife.
A spokesman for Sussex Police said: “We were called at 10.50am today (Wednesday 16 April) to a report that a man was setting fire to a van in Chapel Street, Brighton.
“When officers arrived the van was still on fire and officers visited a property in the road to try to track down the man involved.
“A man inside the property began holding a knife to his own throat so the road was closed while the incident was dealt with.
“A 50-year-old man was later arrested inside the property on suspicion of criminal damage. He is currently in custody.
“Officers are currently at the scene collecting evidence about the incident.
Anyone with information is asked to phone Sussex Police on 101, email 101@sussex.pnn.police.uk or call the independent charity Crimestoppers anonymously on 0800 555111.
Latest TV’s Tim Ridgway tweeted this picture from the scene: