A street is on lockdown after armed police were called to a siege.

STV News understands a man has barricaded himself in a house on Ann Street, Dundee, and is threatening to harm emergency service workers.

Armed police have been called as well as ambulance and fire crews following the alert at 3am on Sunday.

A Police Scotland spokesman said: "We are dealing with an ongoing, contained incident.

"He's in a house and has access to a range of stuff within it and is making threats to emergency workers.

"We have a range of specialist officers at the scene."