Two Norwegian State Television (NRK) journalists were detained by security forces in Qatar for over 30 hours, authorities said Wednesday.

The arrest was made as the two journalists, Halvor Ekeland and Lokman Ghorbani tried to report on worker issues ahead of the FIFA 2022 World Cup to be held in Qatar.

Qatar security forces also deleted footage they gathered at a migrant labor camp. They were accused of trespassing on private property and filming without a permit.

The arrests sparked a diplomatic dispute between the two countries as Norway summoned the Qatari ambassador to the country over the matter.

The two journalists, who returned to Norway following their arrest, said they had verbal permission from those they had filmed.

Norwegian Prime Minister Jonas Gahr Stoere called the arrests “unacceptable.”

“A free press is crucial in a functioning democracy,” Gahr Stoere wrote on Twitter.

“This also shows the importance of this year’s awarding of the Nobel Peace Prize (to journalists). I am very happy that Halvor Ekeland and Lokman Ghorbani have now been released.”

Ekeland, a sports journalist, and Ghorbani, a photographer, had been in Qatar as the country marked one year to go before the World Cup.

“They had gotten all the permissions needed to conduct interviews,” NRK boss Thor Gjermund Eriksen told a news conference at its headquarters in Oslo.

Asked about the Qatar government’s comments about the journalists, NRK said in a statement to The Associated Press that it disagreed and described its journalists as behaving “in line with the principles and ethics of journalism.”