Vietnam's prime minister demanded an investigation and punishment Wednesday over a fire at a karaoke lounge in the nation's capital killed at least 13 people a day earlier.

The blaze started around lunchtime on Tuesday in a crowded residential area on the outskirts of Hanoi. A witness said flames quickly spread to engulf three neighboring houses, sending clouds of black smoke into the air.

It took more than two hours for fire teams to put out the flames to allow rescuers to start searching for victims, the government said in a statement on Wednesday.

Prime Minister Nguyen Xuan Phuc "instructed Hanoi police to soon investigate and find the cause as well as to deal strictly with any violations," the government said in an earlier statement.

Phuc also asked Hanoi city government to close down karaoke parlors and restaurants that fail to observe fire preventive measures.

Officials in charge of fire fighting ordered immediate inspections of public facilities in major cities nationwide, focusing on karaoke parlors, discotheques, bars and restaurants, the government said.

Karaoke is popular in Vietnam and is often picked as entertainment spots for large groups. However, fire drills at such places are rarely conducted and exits are not always provided.