'No imminent threat'
A 31-year-old man was also arrested over the same offence in the Rochdale area.
The six arrested people remain in custody.
The group of nine detained in Turkey included five adults and four children.
Greater Manchester Police said officers were working to establish their reason for travel and apparent attempted entry into Syria.
Officers searched houses in the Rochdale borough as part of the investigation and police said no evidence was found to suggest any "imminent threat" to Rochdale or the rest of the UK.
Greater Manchester Police said in a statement: "Officers continue to work closely with Rochdale Borough Council, local partners, and faith leaders as part of the 'Prevent' initiative."
Footage released on Sunday shows Mr Ahmed leaving a police station in Hatay in Turkey, before getting a coach to Antalya.
His father, Rochdale Labour councillor Shakil Ahmed, said he had thought his son was on holiday.
In a statement he said: "My son is a good Muslim and his loyalties belong to Britain, so I don't understand what he's doing there."