The government-appointed independent commission focused on the events of 25 October, when security forces broke up a protest in southern Narathiwat.
At least 87 Muslim protesters died, including 78 in custody. Most suffocated after being bound and piled into the backs of army trucks.
"Among those responsible are Fourth Army Region commander Lieutenant-General Pisarn Wattanawongkeeree, assistant national police chief Lieutenant-General Wongkot Maneerin and Interior Ministry deputy permanent secretary Siva Saengmanee," commission chairman Pichet Soonthornpipit was quoted as saying in a local newspaper on Saturday.
He said the deaths were due to officials mishandling the situation and not to deliberate acts to kill or harm protesters. He warned that some other unnamed senior figures also shared the burden of responsibility.
The incident sparked international concern and widespread accusations that the government had used excessive force to quell the protest.
Human-rights groups have charged that the detained protesters were stacked on to the backs of flat-bed military trucks, occasionally five deep, and suffocated on the hours-long journey to a military base.
The commission has not indicated what action should be taken towards officials implicated in its report, which Pichet said was unlikely to be made available to the public in its full form.
Apart from the 78 who died during transport, he said seven protesters were shot during the breakup of the riot, while seven others were missing.
The Thai government has been
accused of using excessive force
A video of the protest's suppression has emerged in Thailand.
The government has accused opposition MPs of publicly screening the footage to gain political capital before elections next February.
Thailand's sporadic separatist insurgency sparked back into life in January and since then Buddhists, officials and security forces have been targeted by separatists.
Muslims represent about 5% of the overwhelmingly Buddhist population, but have long complained of discrimination.