Police on Wednesday revealed the progress of their investigation into the shootout at Laksi intersection.
Deputy national police chief Ek Angsananon said the results of crime scene, photos and video clips examination concluded that there were a total 21 people carrying, holding and firing weapons.
Three of the 21 armed men had been identified and police were seeking warrants for their arrest.
Investigators could not yet tell if the three suspects were police or military officers as investigations were still underway.
Police were also looking for a vehicle similar to the cash delivery van suspected of carrying weapons into the Laksi area that was captured on video.
Pol Gen Ek said all the suspects involved in the Saturday’s armed clashes, including any members of the police and military, would be prosecuted.
He said investigators had been speeding up their investigations into other major violent incidents since the clashes in Ramkhamhaeng on Nov 30, but many witnesses in several cases had yet to show up to testify before the police.
In addition, police requests for arrest warrants had been rejected by the court due to insufficient evidence, he added.