Four of those who were killed and 6 injured ones have been identified, Reza Rafei told the Islamic Republic News Agency (IRNA) on Tuesday.
Based on the preliminary investigations the accident happened intentionally, Head of Ahvaz Fire Department Atashpad Torabpour said.
The suspect is said to have been arrested on charge of arson but this has not yet been verified, he added.
The Fire Department was notified of the accident at 1:05 hours local time (20:25 GMT) and firefighters arrived at the scene four minutes later, he earlier said.
According to local people, there were 10 people in the coffeehouse. Three fire fighters and three local people were also injured.
Head of Ahvaz Jundishapur University of Medical Sciences public relations office Farhad Hamzelouei said that the fire casualties count increased to 11 people.
9376**1396
Follow us on Twitter @IrnaEnglish