Portland's mass transit system is the latest to become a forum for the Israeli-Palestinian conflict.
Weeks after a pro-Palestinian group placed an advertisement on Portland buses and trains, a pro-Israel group has replied with an ad it has also been running in New York, San Francisco and Washington D.C.
"In any war between the civilized man and the savage, support the civilized man. Support Israel. Defeat Jihad," reads the ad, which appeared on buses and trains Tuesday morning.