HOUSTON -

A robbery quickly turned violent when one of the victims refused to relinquish his belongings, Houston police said.

It started when a cab driver picked up his fare on Pincay Oaks Drive a little before 1 a.m. Friday. 

According to reports, an armed man approached the driver and demanded his money. 

Police said the suspect took the driver's wallet and cell phone, then turned to the passenger in the back seat and ordered him to hand over his belongings. When the passenger refused, police said a fight broke out.

During the scuffle, the suspect shot the passenger twice and then took off, according to police.

Apparently, the cab driver had never been in that situation before, so he panicked and drove to a Shell gas station on the Southwest Freeway with the passenger still in the back seat.

Officers arrived at the gas station and transported the passenger to the hospital in serious but stable condition.  The cab driver was shaken up but was not injured.

So far, no arrests have been made.