The suspect in a mass shooting during an LGBTQ festival in Norway has refused to explain his actions to investigators and will remain in pre-trial custody for the next four weeks, police and his defence lawyer said.

The man, whom authorities described as a 42-year-old Norwegian citizen originally from Iran, was arrested shortly after the shooting in Oslo’s nightlife district early on Saturday.

He is being held on suspicion of murder, attempted murder and terrorism.

Two people were killed and more than 20 were injured in what the Norwegian security service called an “Islamist terror act”.

Oslo police said they tried to question the suspect on Saturday and again on Sunday without success. Norwegian media identified him as Zaniar Matapour.

Jonas Gahr Store speaks during the service
Jonas Gahr Stoere speaks during the service (Javad Parsa/NTB via AP/PA)

His defence lawyer, John Christian Elden, told The Associated Press by email that his client refused to have his statement recorded and videotaped unless police released the entire recording to the public “with no time delay so it won’t be censored or manipulated”.

Mr Elden said previously said his client did not deny being the gunman but had not divulged any motive.

The lawyer said on Sunday that Matapour did not object to remaining in custody for four weeks so would not appear in court on Monday.

In Norway, pre-trial detention hearings are normally held every four weeks.

Norway’s prime minister and members of the royal family joined mourners at a memorial service on Sunday at Oslo Cathedral for the victims of the attack.

The gunman opened fire at three locations, including outside the London Pub, a popular gay bar in Oslo. Police investigators said it was too early to say whether the attacker specifically targeted the LGBTQ community.

A Pride parade scheduled for Saturday was called off because of the shooting.

Norwegian Prime Minister Jonas Gahr Stoere said during Sunday’s memorial service that “the shooting in the night hours put an end to the Pride parade, but it did not stop the fight and the efforts to fight discrimination, prejudice and hatred”.

He also addressed Norway’s Muslim community.

Norway's Crown Princess Mette-Marit
Norway’s Crown Princess Mette-Marit after the service (Javad Parsa/NTB via AP/PA)

“I know how many of you felt when it turned out that the perpetrator belonged to the Islamic community. Many of you experienced fear and unrest.

“You should know this: we stand together, we are one community and we are responsible for the community together,” Mr Stoere said during the church service, which was also attended by Crown Princess Mette-Marit.

Norwegian media said Matapour arrived in Norway with his family from a Kurdish part of Iran in the 1990s.

He had a prior criminal record that included a narcotics offence and a weapons offence for carrying a knife. Investigators said they seized two weapons after Saturday’s shootings – a handgun and an automatic weapon.

The Norwegian domestic security agency, known by its Norwegian acronym PST, said on Saturday it first became aware of the suspect in 2015 and later grew concerned he had become radicalised and was part of an unspecified Islamist network.

On Sunday, Norwegian media outlets reported that Matapour allegedly was in close contact with an Islamic extremist living in Norway whom Norwegian police had been aware of for a long time.