A San Francisco taxi driver is being sought for allegedly robbing a passenger after a dispute over payment on Saturday night, police said Monday.

The robbery was reported at about 11:40 p.m. Saturday near the intersection of Fillmore and Hayes streets in the city's Alamo Square neighborhood.

The 30-year-old victim was picked up by the cab driver and a dispute developed over the form of payment, according to police.

The taxi driver then pulled out a knife, took the victim's cellphone and credit card and fled alone in the cab, police said.

The driver, a man believed to be in his 30s or 40s, had not been found as of this morning, according to police.

Anyone with information about the robbery is encouraged to call the Police Department's anonymous tip line at (415) 575-4444 or send a tip by text message to TIP411.