A West Bank bike trip of some 400 Palestinians, Israelis and foreigners was cut short at an IDF checkpoint, just moments after it began, participants said Saturday. Judea and Samaria police said that the cyclists had not properly requested permission from Israeli authorities for the ride, and so it was considered an "unlicensed demonstration." They added that one of the riders was detained for questioning. The bicycle tour, organized by the local chapter of the Young Men's Christian Association (YMCA) was meant as a peaceful protest against Israeli occupation of the West Bank and, in particular, the army's system of checkpoints, said organizer Khader Abu Abbara. A network of roadblocks spans the West Bank, often causing delays in travel and disrupting the daily lives of Palestinians. The army says the checkpoints are a key element in its campaign against Palestinian militants. Riders set out Friday morning from the West Bank city of Ramallah and were headed to the desert town of Jericho, some 30 kilometers away. They were stopped at the first army checkpoint, a few minutes outside Ramallah, and were told they could not proceed, participants said. An Israeli rider, Haggai Mattar, 23, said he spoke to soldiers and police in Hebrew, and was given a variety of reasons for why the ride was being halted, including that the bikers had no permit for the tour and that there was concern about their safety. "Everyone gave a different answer," he said. Mattar said the group spent about 90 minutes at the roadblock, trying to persuade the officers to let them pass, before being forced to return to Ramallah. A dozen riders reached Jericho by alternate roads, Abu Abbara said.