OAKLAND -- For the second time in about a week, a passenger on an AC Transit bus was shot Tuesday afternoon while riding a bus in East Oakland, police said.

Police said the victim was shot in the leg by someone on the bus, but an AC Transit spokesman said there are conflicting reports and the gunshot wound may have been self-inflicted.

Oakland Unified School District spokesman Troy Flint said the victim was an 18-year-old senior at Rudsdale Continuation School. He did not have further details about the shooting.

The shooting happened at 1:27 p.m. on a bus near the intersection of Fontaine Street and Crest Avenue, which is not far from Howard Elementary School and the former King Estates Middle School, police said. There were about 12 people on the bus and no one else was injured.

No arrests have been made, police said.

After the shooting, a car drove up and the motorist took the victim away, said AC Transit spokesman Clarence Johnson. The car was stopped by police in the 3100 block of 73rd Avenue, where the victim was then transported by ambulance to a hospital. His condition was not immediately available Tuesday afternoon.

Police said the suspect is described as a black male between the ages of 15 to 20 with a dark complexion and possibly a mustache. He is about 5 foot 7 inches, weighs about 140 pounds and was wearing a blue shirt and blue pants. He was armed with a pistol.

The incident was the second bus shooting in the last eight days. On Sept. 30, someone opened fire on an AC Transit bus that was traveling on International Boulevard headed eastbound for Bayfair Center in San Leandro.

One victim, a man in his 80s, was grazed while getting off the bus at Eighth Avenue, and another man was wounded on board. Both victims were taken to a hospital and recovered from their injuries. Three people who were apparently the intended targets were not hit, police said. After the shots were fired, they told the bus driver to drive away and the bus came to a stop at 15th Avenue, police said. No one has been arrested in that shooting.

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Contact Kristin J. Bender at kbender@bayareanewsgroup.com. Follow her at Twitter.com/kjbender. Staff writers Harry Harris and Natalie Neysa Alund contributed to this report.