FOUR youths were being questioned by police last night after a massive blaze tore through the roof of a supermarket.Kwiksave at Minstergate, Thetford, was left badly damaged by the fire which broke out at around 5pm yesterday afternoon .

FOUR youths were being questioned by police last night after a massive blaze tore through the roof of a supermarket.

Kwiksave at Minstergate, Thetford, was left badly damaged by the fire which broke out at around 5pm yesterday afternoon .

Nearly 100 firefighters from Norfolk and Suffolk tackled the incident, which was hampered by the strong winds fanning the flames.

Last night, a spokesman for Norfolk police confirmed it had been started maliciously, adding: "Four juveniles have been detained."

No details were available about their exact ages or where they were from.

The shop was closed at the time and it is thought the fire was started deliberately at the back of the building and then spread to the roof.

A fire service spokeswoman said: "A lot of smoke was seen around the area and we received several calls."

Fifteen fire crews eventually attended the scene from Norfolk and Suffolk, and turntable ladders were used to tackle the flames from above. Some firefighters wearing breathing apparatus entered the building to fight flames in the first floor offices of the supermarket.

Parts of the roof collapsed during the operation, but the blaze was finally brought under control shortly before 7pm. Crews remained at the scene for some time afterwards damping down and ensuring the fire was completely extinguished.

During the operation, water was used from the Little Ouse river next to the building to dowse the flames.

Fire investigators are expected to return to the scene this morning in a bid to pinpoint the exact cause, while officers will continue to question the youngsters about the incident.

It was not clear last night exactly how much damage had been caused to the inside of the store itself or how it would affect business this week.