A 60-year-old Blenheim man has been charged with arson and burglary following an incident on Christmas Day morning when police say a van was driven into the Blenheim WINZ building.

The man is in custody and will appear in the Blenheim District Court on Boxing Day.

Police are increasing patrols in the Alfred St area of Blenheim following this incident.

Earlier report:

Police and the fire service are investigating an incident about 5am on December 25 when police say a van was driven through the front of the Work and Income building in Alfred St, Blenheim.

Police say it appears an accelerant was then poured around and the building was set alight.

A sprinkler system and alarms in the building immediately activated.

A 60-year-old Blenheim man was arrested at the scene.

He has been treated for smoke inhalation and is now being interviewed by Police.