A month after Israel rescinded a ban on foreign nationals using a main Bethlehem bus line, travelers say authorities are again pulling internationals off buses en route to Jerusalem.

Mid-December, for reasons that remain unclear, tourists leaving the central West Bank city were banned from line 21, a route used predominantly by Palestinian holders of East Jerusalem residency cards.

The ban was briefly lifted over the Christmas holiday, the army said, but foreign nationals say they are again being targeted and removed from the line, the only continuous transport between the two cities.

An American NGO worker told Ma'an that she was inexplicably pulled off a bus as she left Bethlehem to attend church in Jerusalem on Sunday morning, as she does every week. A guard "was deaf to my pleas that I just wanted to go to church," the volunteer said.

Speaking on the condition of anonymity over fears her visa would not be renewed, she said that when she returned to her home in the West Bank, she learned of another volunteer who was pulled off the bus as early as Saturday afternoon.

A bus traveling on Sunday evening carrying a group of five Americans, four Russians (two women and their children), as well as a Japanese and Italian citizen were told to line up next to the highway while guards checked their IDs.

"They kept saying they would explain 'in a second,' telling us to 'go stand over there,'" one of the passengers recounted. "As the bus was leaving without us they said 'you can't take this bus into Jerusalem.'"

Another US citizen, who works for an American aid organization, said one's visa status seemed unrelated to the blanket ban.

"I clearly displayed my work permit to the soldier, identified myself as an aid worker, said I had traveled through this checkpoint before, and he said only that 'it doesn't matter,'" the US aid worker said.

"As a person who is legally registered with a work permit, I felt it was a violation of my rights and the understanding Israel has with international organizations who work here," she added.

The aid worker said she uses the crossing frequently, and recalled with frustration dealing with the apparently random ban in the past. "I knew what was happening; we all know what is going on with this ... but I felt it was arbitrary to just re-start the policy."

The ban also came as a surprise to the bus drivers, who reportedly said authorities made no efforts to explain in advance that they would have to leave ticket-holding passengers standing next to a busy road.

Others say the guards refused to speak English, and were unresponsive when stranded passengers asked for help.

"We were stranded on a highway with no way to cross into Jerusalem. They made no attempt to help us," said another passenger. "They were laughing at us when we asked where we should go, and told us: 'You can walk.'"

For years, foreign-passport holders using public transportation could choose between the tunnel bus, which departs near Beit Jala, or Israel's military checkpoint 300, known colloquially as Gilo or Rachel's Tomb.

Refusing to speak publicly, Israeli military officials confirmed that the ban was first implemented in December. After repeated inquiries, however, Israel has never offered an on-the-record explanation for why the restriction was put in place.

In December, Palestinian Authority security sources said the phenomenon follows a unilateral decision by Israeli authorities made months ago to ban foreigners from the route. It was not clear, however, who ordered the changes, or why.

Israeli army officials have also insisted they had nothing to do with the plan, but officials in the country's Border Police, the paramilitary branch of the Israeli Police, said such orders could only have come from the military.

"The [army] commander makes the policy; we just implement it," said a border guard official who insisted on anonymity. "If the IDF says we can't allow foreign people – it's a policy."

However, the ban appears to apply only to Palestinian buses in the West Bank. Foreign nationals traveling on Israel's Egged service, which connects the country's settlements throughout the occupied territories, including in Bethlehem, into Israel, have reported no problems at the tunnel checkpoint. Internationals in private cars were similarly unaffected.

It was not clear if the initiative to limit foreigners' movement in the region was linked to prior passport restrictions. Mirroring the treatment received by Palestinians already living under the four-decade occupation, similar restrictions on foreigners first came to light in September when Israel began issuing visas that permit travel only in PA-controlled areas.

When Israel temporarily reversed the ban in December, a security source said the checkpoint would be open to foreigners at least until the end of January. After that, it will be "up to the political echelon" to decide whether to keep the route open, the source said.