Police are negotiating with a 40-year-old man who is on the window sill of a house in north Liverpool.
The force was called out to Sharpville Close in Kirkdale at around 12.10pm today following reports of a "domestic incident."
A section of Lambeth Road between the junctions with Stanley Road and Maregreen Road remains closed by police while they dealt with the scene in nearby Sharpeville Close.
Photographs from the scene showed a large police presence in the area.
Police urged the public to avoid the area while they dealt with the scene.
A police spokesman said to the ECHO : "We are currently attending to an incident in Kirkdale.
"Officers were called to Sharpville Close at around 12.10pm following reports of a domestic incident .
"A 40 year-old man is currently on the window sill of a property and a police negotiator is at the scene.
"Emergency services are in attendance and a cordon is in place.
Travel Monitor Inrix states: "Lambeth Road in both directions closed due to police incident between A567 Stanley Road and Westminster Road. Traffic is coping well.
"The road remains closed, having been shut since 14:20. Buses are diverting along Fountains Road in both directions."
It is not known when the road may reopen.
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"Members of the public are advised to avoid the area while the incident is dealt with."