Police are investigating after a threat to Christchurch mosques was made online.

Photos posted on a website this morning mentioned "doing something like what happened on March 15 last year".

Islamic Women's Council of New Zealand Anjum Rahman said they have alerted community leaders and asked police to increase security around mosques.

Rahman said it's not the first threat they've received.


A police spokesperson said they are aware of the threat and inquiries are ongoing.

"Police are working closely with the organisations involved and we have the common aim of ensuring the safety of our communities."

He said for "operational reasons" police would not be providing details about security matters before March 15, the first anniversary of a massacre that killed 51 people at two Christchurch mosques.

- Newstalk ZB