Chief Minister Anandiben Patel had entrusted the CID Crime Branch to take up the case 10 days ago. It immediately picked up eight persons.
Earlier, the local police in Una had nabbed 16 persons, who were accused of lynching the Dalit youth in full public view.
The incident was captured in a video which went viral on social media, triggering outrage.
On Friday, two more accused, Kishoresinh Rathod from Kanak Barad village and Shivbhai Sankhat from Umej village were arrested. Four others were arrested on Tuesday.
Meanwhile, the four victims who were shifted to the Government Civil Hospital in Ahmedabad from Rajkot on Wednesday after one of whom vomited blood were also being given psychiatric treatment as they had undergone severe trauma because of the incident.
A doctor said: “The boys were under post-traumatic stress and have developed sleep disorder.”
Besides the regular treatment, a team of two psychiatrists and two psychologists has been formed to assist them.
The flogging had triggered violent protests across the state during which a large number of vehicles and public property were damaged.
A police head constable, who received head injuries during a clash with the protesters, also died.
The incident was raised in Parliament and several political leaders, including Congress Vice President Rahul Gandhi, Delhi Chief Minister and AAP leader Arvind Kejriwal, visited Mota Samadhiyana village to express solidarity with the victims’ families.