An explosion has gone off at a Swedish apartment, sparking a police investigation, the Mirror says.

The blast occurred at a flat in central Malmo on Thursday, July 28, at around 10pm local time, it is reported.

The impact smashed several windows, although it is unclear whether anyone was injured.

Emergency crews are currently at the scene, while residents have been ordered to stay indoors.

A police spokeswoman said several roads have been cordoned off in the wake of the explosion.

She added that the cause of the blast remains unclear, the Mirror reports.

It comes two days after an unidentified assailant shot and wounded a man in a shopping mall in the same city. A Malmo police statement said the victim was shot in the leg and taken to a local hospital. His condition remains unknown.

Police said they had not identified a suspect or motive in the shooting and had made no arrests.

A police spokesperson later told Sydsvenska Dagbladet that the incident, which took place in a mainly immigrant neighborhood of Sweden's third largest city, was being investigated as a case of aggravated assault or attempted murder.