STOCKHOLM, March 26 (Xinhua) -- Many people were injured and others remain missing after an apartment building in Norway's west coastal city of Aalesund collapsed on Wednesday, NTB news agency reported.

    Some 20 people were believed to have been in the building that collapsed in the early hours of Wednesday morning, said the police.

    None of those brought to hospital so far had serious injuries, NTB said.

    Rescuers, as well as a helicopter, were called to the scene in Aalesund, about 350 km northwest of Oslo, according to the Joint Rescue Coordination Center for Southern Norway.

    The area around the six-story building has been cordoned off and nearby buildings were also evacuated.

    According to reports of the Norwegian public broadcaster NRK, the collapse occurred after a large section of the mountainside behind the building slid into the ground floor and pushed it several yards onto the street.

    Police and rescue teams are trying to search the ruins for survivors, but a gas leak made the operation difficult and complicated, NRK said.

    It said that around 15 people have been brought to hospital with minor injuries, while five others are still missing.