MTA officials say two MTA workers were attacked only an hour apart on Friday.

They say the first attack happened on the 6 train around 10:40 a.m. A conductor was punched in the face and splashed with a liquid that was believed to be urine.

The second attack happened an hour later at a BX1 bus stop, where a suspect splashed an MTA bus driver with what was also believed to be urine.

The Public Transport Union president said in a statement, "We will do everything we can to help the police catch this disgusting individual and put him in handcuffs."

MORE: Police: Man tossed cup of urine at MTA driver

The union says it believes that the suspect is a serial attacker targeting women.

New York City Transit President Andy Byford said, "I've asked NYPD to step up patrols in response to the subway incident in addition to our prior request to increase police presence on buses, and we will do whatever we can to help NYPD identify the perpetrator or perpetrators..."

MTA officials urge their workers to be on alert throughout the day.