On the day of the city's annual Pride parade, terrified revelers at a gay pub in Oslo huddled in a cellar and anxiously contacted loved ones as a gunman opened fire, killing two and wounding more than 20.

Victims were shot inside and outside the London Pub, a longtime core of Oslo's LGBTQ scene, in the nearby streets, and at another bar in the heart of the Norwegian capital. The incident occurred in the early hours of Saturday morning.

Bili Blum-Jansen, who was in the London Pub, stated that he and 80 to 100 others huddled in the basement to escape the shower of gunshots.

"I was terrified and believed that if the gunman or shooters arrived, we would all perish. There was no escape."

A suspect, a 42-year-old Norwegian citizen of Iranian descent, was apprehended minutes after the shooting spree, according to the police, who think he acted alone.

They stated that two firearms, one a fully automatic gun, were recovered from the crime scene.

There are indications that this may be a hate crime, according to the authorities.

"We are investigating whether the Pride was a target in itself or whether there are other motives."

Later, Norway's PST intelligence service stated that the suspect, who was known to authorities, is considered to be a radicalized Islamist with a history of mental illness.

Other witnesses reported the commotion inside and outside the 1979-established London Pub.

"My first thought was that Pride was the target, so that's frightening."

NRK journalist Olav Roenneberg said he was in the neighborhood at the time and observed a man approach with a suitcase, pull out a gun, and begin firing.

"Then I saw windows breaking and understood that I had to take cover," he claimed.

Authorities stated that the attack was also being investigated as a possible terrorist act and that mental illness was not ruled out as a role.

'We're here, we're queer, we won't disappear'

As a precaution, the typically unarmed Norwegian police will henceforth carry firearms until further notice, according to national police chief Benedicta Bjoernland.

The Norwegian PST intelligence service stated that it was studying the possibility of additional assaults but that there were currently no indications of this.

Citing police advice, the organizers of Oslo Pride canceled Saturday's parade.

"We will soon be proud and visible again, but today we will mark Pride celebrations at home," they stated.

Nonetheless, many thousand individuals launched what appeared to be an impromptu march in central Oslo, carrying rainbow flags and screaming, "We're here, we're queer, we won't disappear."

In a Facebook post, Prime Minister Jonas Gahr Stoere described the shooting outside the London Pub in Oslo as "the shooting outside London Pub in Oslo tonight was a cruel and deeply shocking attack on innocent people."

Although the motivation was unknown, he stated that the shooting had instilled dread and sorrow in the LGBTQ community.

The shooting occurred just months after Norway celebrated the 50th anniversary of repealing legislation that criminalized gay sex. The suspect was known to authorities, including for lesser acts of violence, according to police.

The Nordic nation of 5,4 million people has lower crime rates than many Western nations. However, it has witnessed hate-motivated attacks, including the 2011 murder of 77 people by far-right fanatic Anders Behring Breivik.