Assistant Chief Constable Steve Cotterill said "please do not see these two arrests as the police inquiry coming to an end" and appealed to the public for additional information.
He said: "I need additional information from the public out there to really get to the truth to what was the reason behind that fire - whilst I know the cause I do not know the reason behind it and I'm still anxious for that information to come forward."
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Two private citizens have already paid a "significant deposit" to take the week-long trip.
Slippy start tomorrow with frost & ice
The court will determine how much the UK government and travel firms knew about the risk of an attack on tourists holidaying in the area.