Israeli police have detained six Palestinians dubbed West Bank Freedom Riders who boarded a Jerusalem-bound bus used by Jewish settlers.
The activists say they drew inspiration from 1960s US civil rights demonstrators who campaigned under the same name against segregated buses.
Palestinians from the West Bank are not allowed to cross into Jerusalem without Israeli permission.
Israel says such restrictions are for security reasons.
The group of six protesters gathered at a West Bank bus stop and waited for an Israeli bus to pick them up, then tried to enter Jerusalem, in what appears to be a first.
After being allowed to travel to an Israeli checkpoint at the edge of Jerusalem, the activists were eventually arrested when they refused to leave the bus.
The protesters say that by only serving Jewish settlements and not Palestinian areas in the West Bank, Israeli bus companies discriminate against them.
"These buses and this whole system is discriminatory to Palestinians," said activist Fadi Quran, as he waited at the bus stop.
The West Bank Freedom Riders punched above their weight, drawing a lot of publicity for what was a relatively small event, reports the BBC's Jon Donnison in the West Bank.
The comparison to the Freedom Riders of 1960s America seemed to capture the imagination as dozens of journalists gathered to see the small group board the bus, our correspondent says.
In actual fact, this was less a protest about segregation and more about freedom of movement, he adds.
There are around 500,000 Jewish settlers in the West Bank and East Jerusalem.
Settlements are illegal under international law although Israel disputes this.