QUICK-thinking bystanders took swift action to save a Suffolk church from extensive fire damage.

Police have launched an arson investigation after a blaze broke out in the vestry of St Andrew’s Church in Westhall, near Halesworth.

It is understood that two men were sketching the church when they discovered the fire shortly before 6pm on Tuesday.

Firefighters arrived shortly afterwards and contained the flames in the vestry but damage was caused to some cupboards and a wooden dividing wall.

Police now need to trace two people seen entering the church shortly before the fire was detected.

A white woman in her 60s to 70s, with light collar length hair and blue dress or skirt, and a white boy around 16, 5ft 6in, with curly brown hair and wearing shorts and a black long-sleeve T-shirt, entered the church around 5.30pm and may have left in a silver people-carrier type vehicle.

Witnesses reported the teenager running around inside the church before smoke was spotted.

A police spokeswoman said: “We are treating the incident as suspicious and are trying to determine exactly what happened. We are keen to speak to anyone who may have information.”

The fire is believed to have started in a box of candles, but it is not known what caused the box to ignite.

The Reverend Canon Paul Nelson, rector of the Hundred River Benefice, a group of nine Church of England parishes in north Suffolk including St Andrew’s, arrived at the scene with fire crews.

He said: “It’s too early to determine the cost of damage. Though very annoying and unnecessary, the damage would have been far more serious had it not been spotted and put out quickly.

“The vestry is a private screened and curtained area but there is nothing stopping the public from entering.

“We are obviously grateful to the two young men for their quick thinking and action.”

Police are asking the woman and boy, or anyone with information about who they are to come forward. Officers would also like to hear from anyone who may have any information about the incident. If you can help, call Halesworth police on 101.