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 a 25-year-old man and 33-year-old woman after executing a search warrant at a Treelands Crescent home about 1pm yesterday.

Both have been charged with reckless wounding in company and were refused bail to face 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.