Two people were hospitalized and more than 100 residents evacuated after a fire broke out in a building in east London that is partly used as an apartment block.

The London Fire Brigade (LFB) said scaffolding around the building in Freshwater Road, Dagenham, as well as parts of the building up to the sixth floor and the roof, were on fire when it was called at 02:44 BST.

Four people were treated at the scene by the London Ambulance Service (LAS), two were taken to hospital.

The cause of the fire is not yet known, LFB said.

Thick, black smoke is pouring out of the building and flames are occasionally flaring up.

The cause of the fire is not yet known, but the BBC believes that the building’s “non-compliant” cladding had just been removed.

All parts of the building are said to be affected by the fire, including a daycare center in one of the business units on the ground floor.

A “significant” search and rescue operation is underway, the LFB said.

A man whose six-year-old daughter was staying with friends in the building told the BBC they were “calm now but scared” when the fire broke out.

Dinesh Raj said he received a call around 3 a.m. that the building was on fire and rushed to the scene in his car. He said the family immediately got out when they smelled smoke, taking their six-month-old baby and daughter with them.

By the time they left the building, the fire had already spread to the top floor, he said.

40 fire engines and 225 firefighters were dispatched to Freshwater Road, which was closed to traffic. The fire service used a drone to determine where to concentrate emergency services.

Station manager Alan Bendell is on site and said: “The fire is producing heavy smoke and we advise residents to keep windows and doors closed.”

“Two of the brigade’s 32-metre-long turntable ladders are being used on site as aerial water towers to support firefighting from heights.”

Several ambulances are nearby and the LAS said a rescue helicopter has been dispatched.

“We treated four patients on site and took two of them to hospital,” said an emergency services spokesman.

Crews from Dagenham, Ilford, Romford, Barking and surrounding fire stations are on site.

LFB describes the property as a “mixed-use residential and commercial building”.