Two women, aged in their 20s and 30s, and a man in his 30s were arrested by gardaí this afternoon. They are being held at Tipperary and Cahir Garda stations.
Earlier this morning, a man, who is understood to be in his 20s, and a woman who is in her 40s were arrested in Waterford.
A post-mortem examination was due to be carried out today on Mr Stokes' body.
A murder investigation has been launched after the fatal stabbing.
Gardaí say Mr Stokes, a married father of four, was stabbed a number of times while sitting in his van with his 11-year-old son shortly after 6pm yesterday.
It is understood that he tried to flee from his attacker or attackers but crashed his vehicle on Bridge Street where he was pronounced dead sometime afterwards.
The horse dealer, who had not come to garda attention before, was described as a gentleman.
Mr Stokes was a member of the Traveller community and had lived in Tipperary for the past 20 years.
Gardaí in Tipperary have appealed to anyone who was around the Supervalu in Tipperary town from 9am yesterday until 7pm last night to contact them.
The motive is still unknown, but one line of enquiry is that the killing may be linked to an ongoing feud between members of the Traveller community in Waterford and Tipperary and may have been planned.
It is suspected that Mr Stokes, though not involved in the row, may have become an innocent victim of it.
The investigation is being led by local detectives in Tipperary, assisted by investigators from Dublin and Waterford.
