At least 120 firefighters are tackling a rooftop blaze at a south London museum.
Crews on 20 fire appliances have been called out to Southwark Council's Newington Library and the Cuming Museum near Elephant and Castle.
Peter John, leader of the council, said: "A fire has broken out in one of our buildings which houses the Cuming Museum, the home of the worldwide collection of the Cuming Family and the museum of Southwark's history.
"The building also houses a library and a one-stop shop for residents to access council services. Everyone has been evacuated and there are no reported injuries.
"It is too early to say what the cause of the fire is and how long services from that building will be suspended for. It does not appear that surrounding buildings or residential properties have been affected but we will continue to monitor the situation very closely and continue to assist the emergency services where we can.
"While our first concern is for the safety of residents and our staff, we are also worried about possible damage to the museum's collection."
Nearby Walworth Road and shops along it are shut, the council added.
Peter Critchell, of the London Fire Brigade (LFB) said: "Flames are coming through the roof and there is thick grey smoke billowing up. Firefighters are still working hard at the scene to try and bring the blaze under control.
"We now have water jets attacking the fire from the four corners of the building. We evacuated 30 people from inside the museum and firefighters will be making efforts to salvage as many of the artefacts as possible. "
Dany Cotton, LFB's assistant commissioner for operational assurance, added: "We've got well over 100 firefighters at the scene to bring the fire under control.
"It's large blaze and the whole of the building's roof is alight."