Police are looking for a man they say sprayed an unknown substance at two MTA bus drivers.

Both incidents happened just hours apart on the B15 bus in Brownsville Thursday.

Police say the man in these photos sprayed one driver at Rockaway and Hegeman Avenues and the other near East 98th street and Blake Avenue, before running away.

Both drivers and two passengers were taken to the hospital and later released.

Transit president Andy Byford issued a statement saying that MTA employees and customers deserve a safe environment, and urged them to contact police with any information.

Anyone with information on the case should contact the Crime Stoppers hotline at 1-800-577-8477, or text CRIMES and then enter TIP577, or visit www.nypdcrimestoppers.com.