Rescue workers carry a victim to an ambulance after a massive fire ripped through an apartment block in Hanoi early Friday
Rescue workers carry a victim to an ambulance after a massive fire ripped through an apartment block in Hanoi early Friday AFP

A fire ripped through an apartment complex in central Hanoi early Friday, killing 14 people and injuring three others, police said.

Smoke and toxic gases billowed out of the building in Cau Giay district, a densely populated district of Vietnam's capital that is home to several universities, after a fire broke out around 12:30 am (1730 GMT Thursday).

Rescuers forced their way inside, breaking the lock of an external gate and smashing a window to rescue seven people trapped inside.

Neighbours reported hearing explosions "like firecrackers" and screams from people inside and those living close by.

"The fire grew strongly, destroying many motorbikes, electric bicycles, and bicycles in the yard area," Hanoi police said in a statement.

"By 1:26 am, the fire was completely extinguished. Rescue forces discovered 14 people dead."

Three survivors were receiving emergency treatment in hospital.

The building's corrugated metal roof caved in as the blaze reduced the complex to a charred shell open to the sky, strewn with blackened belongings and bike parts.

Twenty-four people were officially registered as living in the complex.

The building comprised two interconnected blocks, one with two storeys and the other with three, situated down a two-metre-wide alley, with 12 rooms for rent.

The courtyard was reportedly used for selling and fixing electric bicycles.

A neighbour, who declined to give her name, told AFP she heard an "explosion like firecrackers".

"I thought there was a fight, or something hitting the window. I ran down and saw the fire.

"Many of the neighbours had run out of the alley, crossing through other neighbours' houses. We were so, so scared."

She said the building's landlord rescued his daughter-in-law and a grandchild from the flames.

One survivor who lived with his wife on the second floor told news site Dan Tri that they awoke as fire and smoke began rising fiercely from the first floor into the hallway outside their room.

"The heat from the fire was absolutely terrible," the man, who declined to be named, said.

"The smoke and fire were so intense, my wife and I went back to our room, crawled into the bathroom, and I used a wet towel over my nose to breathe.

"After about an hour of doing that, we were rescued and taken to the hospital."

Another neighbour, Ngo Thi Thuy, said she saw flames rising up through the cracks of the building's corrugated metal roof.

"Fire particles kept flying, the smoke was so thick that it was impossible to see anything," Thuy, 40, told state news site VNExpress.

"There was the sound of explosions and some screams. The screams were coming from inside the burning house and surrounding houses."

Along with her other neighbours, she poured buckets of water onto the roof -- but said the smoke only rose higher.

Authorities are still investigating the cause of the fire, the latest deadly blaze to hit the communist country.

In Vietnam's deadliest fire in two decades, 56 people died -- three of them children -- in a Hanoi apartment block blaze last September.

The country has experienced several other deadly fires in recent years, often at entertainment venues.

A year ago, a karaoke bar blaze near commercial hub Ho Chi Minh City killed 32 people and injured 17. The owner was later arrested on charges related to breaching fire prevention regulations.

In the aftermath, the prime minister ordered an inspection of all high-risk venues.

Fire safety equipment and instructions have been installed in many streets and buildings across the city.

The Hanoi apartment complex was reduced to a charred shell
The Hanoi apartment complex was reduced to a charred shell AFP
Victims rescued from the blaze were being treated at a hospital in the capital
Victims rescued from the blaze were being treated at a hospital in the capital AFP