Gwinnett County fire investigators are trying to determine what sparked a Wednesday morning blaze that damaged a business near Norcross.

The fire was reported about 2 a.m. at The Mughals, a Pakistani restaurant in a strip shopping center in the 5200 block of Jimmy Carter Boulevard.

Gwinnett fire Capt. Tommy Rutledge said the initial call was for a woods fire behind the shopping center, but firefighters "encountered heavy fire" inside the restaurant. Flames had spread undetected until smoke became visible from outside the building and prompted 911 calls, he said.

"The blaze gutted the business and caused extensive damage," Rutledge said.

The fire appears to have started in the kitchen, according to fire investigators, who still have not determined an exact cause.

No foul play is suspected at this point, Rutledge said.

There was no one at the restaurant when firefighters arrived, and no injuries were reported.

--Dispatch editor Angel K. Brooks contributed to this article.