WELLINGTON, March 17 (Xinhua) -- New Zealand Prime Minister Jacinda Ardern said on Sunday that the bodies of those killed in terror attacks on two Christchurch mosques were beginning to be returned to their families but only a small number at this stage.

The suspect Brenton Tarrant was being held in a high- security facility, Ardern told a press conference.

There would be an increased police presence in Christchurch, the country's second largest city on Monday, with an extra 120 officers, she said, adding all mosques would be guarded by the police.

Specialist teams would be at Christchurch schools and early learning centers, and support lines are also available to anyone who needs it, Ardern said.

The parliament would also pay tribute to the victims on Tuesday.

Ardern paid tribute to police, hospitals, first responders and teachers following the mass shooting.

She said she would not stop the sales and advertising of firearms, as has been suggested by academics.

A gunman stormed two mosques in Christchurch on Friday afternoon, killing at least 50 people and injuring 50 others.