The attacks took place across Havant and Bedhampton, with at least six areas being hit during the two-hour spree.
Dozens of firefighters from Havant, Emsworth, Waterlooville, Cosham, Portchester and Southsea were mobilised to tackle the multi-blaze attack, which began just before midnight.
The focus of last night’s mobilisation was at Awbridge Road, Bedhampton, where a number of vehicles were torched.
Hampshire police said the force had been alerted by Hampshire Fire and Rescue Service at about 12.36am after two caravans, three cars, a flatbed truck and a tree were damaged.
A spokeswoman added two boys were now being questioned by officers, saying: ‘We can confirm that we have arrested a 16-year-old boy on suspicion of six counts of arson and a 17-year-old boy on suspicion of six counts of arson and assault of a police officer.
‘The boys are both in custody.’
Police are still appealing for witnesses to the incident, or those with any information, to call 101 quoting reference number 4180150282.