A Pakistani is believed to have shot and killed all three of his sisters at the family's home in Oslo

Nina Berglund:

The three sisters, aged 13, 24 and 27, lived in the flat in Oslo's Kalbakken district with their three brothers, their wives and children. The 30-year-old brother was the oldest, and police said he functioned as head of the household when the retired patriarch of the family was on one of his trips to Pakistan, as he was this week.

Police said they received a call Sunday night from one of the younger brothers in the home, and he reported "the shooting of a woman." When police arrived they found all three sisters dead.

The eldest brother had fled but was captured within a half-hour and and reportedly told police "it's probably me you're looking for," before he passed out.

He was rushed to the Oslo emergency clinic (Legevakt) and later to Ullevål hospital. Police said they still hadn't been able to question him, because his condition was too unstable.

Police said they therefore had no motive for the murders. Neighbours also described the shootings as baffling, describing the family as "very nice" and "completely normal," noting that they often invited neighbours in for Pakistani food.

Some friends of the sisters, however, told Norwegian Broadcasting (NRK) that there had been "a lot of quarrelling" within the family.

Investigators from Norway's special crime unit Kripos worked through the night to secure evidence. A police spokeswoman said a pistol was found at the scene that is believed to be the murder weapon.

The sisters' bodies were reportedly found in different places around the flat.

Three sisters with Pakistani back ground shot dead in Norway