UPDATE 11:28 P.M.
Fire has been knocked down by 11 p.m., per reports. Fire crews are doing overhaul and looking for hotspots.
Witnesses said fire began under the "Pharmacy" sign on the outside of the building, ran up to the roof and then through the roof into the store.
Montgomery County Health Department is on scene as well.
There are no injuries in the fire. All employees and customers were safely evacuated, officials said.
Montgomery Township Fire Marshal's Office and FDMT officials continue to investigate the origin of the fire as of Monday morning.
Fire Department of Montgomery Township and other stations are battling a two-alarm roof fire at Assi Market at Assi Plaza on Welsh Road in Montgomery Township that broke out shortly after 10 p.m. Sunday.
PhillyFireNews.com reports the roof fire has extended into the building. The Firefighter Assist and Search Team has been actived to aid FDMT.
FDMT is assisted at the scene by Colmar Fire Co., Hilltown Township Fire Co. of Line Lexington, Fairmount Fire Co. of Lansdale, Horsham Fire Co., Hatfield Fire Co., North Penn Fire Co., Wissahickon Fire Co., Centre Square Fire Co., Warrington Fire Co., Chalfont Fire Co. and Ft. Washington Fire Co.
Stay tuned for updates