The SFPD made an arrest Wednesday in a knife attack that may or may not have stemmed from the victim refusing to give a random stranger money when he asked for it.

The story looked on the surface like, perhaps, a disagreement between two acquaintances or associates, perhaps over drugs. San Francisco police say they were flagged down Wednesday morning around 10:30 a.m. on the 200 block of Powell Street after a 34-year-old man sustained a serious knife wound to his face. As KPIX reports, the suspect was a six-foot-tall white man with shoulder-length blond hair, a mustache and full beard.

Allegedly, the suspect approached the victim on Powell Street, just south of Union Square, and asked him for money. When the victim said he didn't have any, witnesses say the suspect became enraged, began yelling, produced a knife, and slashed the victim's face.

As KTVU reports, via the police, the wound is not life-threatening but it is "extremely severe."

Police immediately put out calls and posted tweets with photos to try to locate the suspect, and he was spotted by officers from SFPD's Ingleside Station later on Wednesday. They arrested the suspect, who has not been publicly identified but is said to be in his 30s.

Police have not clarified whether the two men knew each other.

If the two did not know each other, the case potentially represents a new escalation in street violence in the city — just feet from Union Square — and a new extreme in aggressive panhandling.

We'll update this story as we learn more.