Detective Inspector Keith Gawley said the incidents happened at police officers’ homes between April and July last year in Banbridge, Portadown, and Gilford areas last year.
A number of victims had their vehicles and homes attacked, and in some cases their property was gutted.
Six men and three women, aged between 20 and 51, were arrested on suspicion of offences including arson with intent to endanger lives and drugs offences.
They were detained after police carried out a number of searches in properties in the Larne, Lisburn, Armagh, Banbridge and greater Craigavon area this morning, Tuesday, February 21.
They are also being questioned on suspicion of theft and conspiracy to cause an explosion.
DI Gawley said: “This investigation also focuses on offences involving drugs.
“The suspects have been taken to Musgrave Police Station for questioning and a number of items have been removed for further examination.
“I would appeal to anyone who has any information relating to these arson endangering life incidents or any drug activity to contact detectives at Mahon Road.”