A 15-year-old boy has been arrested and charged in relation to an aggravated robbery in Christchurch.

Police said today they had arrested the teen following the robbery at a petrol station on Ferry Road, in Woolston, at about 10pm on Sunday.

It is alleged he threatened staff with a knife before fleeing the store with an unrevealed amount of money.

He will appear in the Christchurch Youth Court on Tuesday.