Three people were killed and five injured in the shooting on a tram in Utrecht.
PM Jacinda Ardern says detail of gun law reforms will come within days after Christchurch attacks.
Police are investigating what happened at an event for youngsters at a hotel in Cookstown, Co Tyrone.
Farid Ahmed's wife Hosne, 44, was killed while searching for him in Christchurch.
The prime minister is seeking to persuade MPs to back her Brexit deal at the third time of asking.
Others arrested after the attacks in Christchurch that killed 50 are not believed to be involved.