COPENHAGEN, Denmark (AP) — A man has been charged in Norway for his alleged role in plans to carry out three extremist attacks in Denmark and in London, and for purportedly spreading Islamic State group propaganda on the internet.

Authorities believe the 24-year-old man, who wasn’t identified, was part of a group that sought to strike a church in England, possibly St. Paul’s Cathedral in London, but British police thwarted the plot, Norwegian broadcaster NRK reported Monday.

The man was also allegedly involved in plans for one or more attacks in Denmark in March and April 2019 with help from at least one Danish citizen, prosecutor Geir Evanger told NRK. Those attacks are believed to have been prevented as well.

The man has maintained his innocence. If found guilty, the man who claims to be innocent, faces up to 21 years in jail, NRK said. The trial starts in Oslo on May 18.

Evanger was quoted as saying by NRK that as to his involvement in IS, the man spread “extremist material, violent material and material with religious content” online. He was an administrator for several groups on social media, including some he had created, the prosecutor said, adding they consider him to be “a relatively central participant in many of these groups.”

NRK said the man had been held in custody for a while.

It wasn’t immediately known whether the case was linked to the July sentencing in London of Safiyya Shaikh, a British woman who had converted to Islam. She was jailed for life, with a minimum sentence of 14 years, for plotting to blow up St. Paul’s Cathedral, a nearby hotel in London and a subway train in a suicide attack.

Shaikh, born Michelle Ramsden, who was a supporter of the Islamic State group, pleaded guilty to terrorism offenses.