A 59-year-old woman was in serious condition after she was apparently pushed into a moving city bus in Chinatown.

Roger Morton, president and general manager of Oahu Transit Services, said two witnesses outside the bus saw a man push the woman, who hit the side of an articulated city bus and then hit her head on the sidewalk.

He said the Route 1 bus was traveling about 5 mph at the time, in an unknown direction on Hotel Street near Kekaulike Street Friday afternoon. The bus immediately stopped, and the 50 passengers onboard had to get off and transfer to another bus, he said. No one on the bus was hurt.

Police said a man was arrested, but did not immediately have further information.

Paramedics took the woman to the hospital in serious condition, an Emergency Medical Services supervisor said.

Morton said he didn’t know why the man pushed the woman or if he intended for her to fall against the moving bus.

"It’s the first time I’ve heard of something like this occurring," he said. "We’re obviously shocked as everyone else is."