A man was attacked and robbed Thursday night, when a pair of women started an altercation with him then stole his medication.

Police say that the incident happened at around 9 p.m. Thursday, on the first block of Sixth Street, which is between Market and Mission Streets.

According to the San Francisco Police Department, the 64-year-old male victim was approached by two women — one who looked to be in her 60s, and another who looked about 20, witnesses say.

The victim "got into a verbal altercation with" the woman, police say, an argument that turned violent when the older woman pepper sprayed the man in the face.

As the man reacted to the attack, the younger woman grabbed a bag he was carrying, police say, which contained a package of laxatives.

The women then fled in foot in an "unknown direction," police say, purgatives in hand. As of Friday morning, they remain at large, and no arrests have been made in the case.