Finnish prosecutors say a man and woman arrested for allegedly plotting an attack at Finland's biggest university were planning to kill dozens of people.

Authorities have released few details about the pair or their alleged motive since they were arrested in March.

Footage from Finnish broadcaster YLE showed the woman raising her right arm in an apparent Nazi salute at the start of a court hearing Monday.

Prosecutors told the court that the defendants, whose names were not released, were plotting to kill about 50 people in an attack at the University of Helsinki.

They were also charged with weapons possession.

Both have pleaded innocent.