Christchurch is reeling after yesterday's terror attacks.

A gunman opened fire at two mosques in the city yesterday.

Forty-nine people were killed and 42 are being treated for injuries, including a four-year-old who's being taken to Starship hospital.

Christchurch Mayor Lianne Dalziel told Mike Hosking the city is in shock.

"I think it's going to take a long time to actually sink in, the extent of what we have suffered."