A total of 36 people were convicted in the case.
The court said that the five met with their close relatives before the execution. Thus, "the executed criminals legal rights were fully protected,” it added.
According to the verdict, the gang, headed by Liu Ghanem "illegally monopolized the gaming business in Guanghan city in Sichuan province, tyrannized local people and seriously harmed the local economic and social order."
In recent months, several top officials from Sichuan province have come under scrutiny.
Sichuan is believed to have been a power base of Zhou Yongkang, China's former domestic security chief who is now the subject of a corruption probe.
Zhou became a head of China's public security ministry in 2003 and oversaw China's security apparatus and law enforcement institutions.
He was arrested in December 2014, the latest and by far the most senior figure to be handed over to prosecutors as part of President Xi Jinping's crackdown on corruption.