Reports are coming in of a serious crash on SH29A, near Maungatapu.

Details are limited, but SunLive understands police are at the scene of a crash.

A caller to the 0800 SUNLIVE news hotline says the road is blocked and police will be stopping traffic at Baypark and Maungatapu roundabouts.

The caller says people should use an alternative route to avoid getting caught up in any traffic.

The NZTA says northbound traffic is being detoured via SH2A to SH2 and southbound traffic is advised to continue with SH2 and take SH2A for SH29 or SH36.

We are working on getting more information and will update this story as soon as we have something more.