A man and woman have been charged over the machete attack that left a 22-year-old man seriously injured in Ballina on Sunday night.

Police arrested Akeiam Dennis Cook, 25, and his aunt, Tahnee Lois Daley, 33, both of Ballina, after executing a search warrant at a Treelands Crescent home about 1pm on Tuesday.

Both were charged with reckless wounding in company. Cook is alleged to have been the passenger on the e-bike who produced the machete and struck the 22-year-old victim.

The pair appeared in the Bail Division on Wednesday. Daley was granted conditional bail and is due to appear at Ballina Local Court on September 3, while Cook remained in custody and was due back before the court today.

The charges follow an attack in River Street about 7.55pm on Sunday.

Police allege the 22-year-old victim was approached by two people riding an e-bike and, following a brief discussion, the passenger produced a machete and struck him on the lower right leg.

The pair then left the scene.

NSW Ambulance paramedics treated the injured man for a laceration to his lower right leg before taking him to Lismore Base Hospital in a serious but stable condition.

Police now say they believe the accused man and woman are known to the 22-year-old.

The attack was one of two knife incidents in Ballina within about six hours on Sunday.

Earlier that afternoon, police responded to an incident at Ballina Central after a shopper was allegedly threatened with a large knife outside Coles.

The incidents came just days after Richmond Police District conducted a targeted shoplifting and knife-scanning operation at shopping precincts in Ballina, Lismore and Goonellabah.

Police located four knives during the two-day operation, three of which were seized.