U.S. authorities have arrested and detained Canadian and European travelers at U.S. borders in recent weeks. German tourist Lucas Sielaff says he spent 16 days in detention in San Diego before being allowed to return to Germany. He says he was accused of living in Las Vegas with his American girlfriend. Sielaff says he lives in Germany and never overstayed his 90-day authorization to visit the U.S. At least three other international travelers say they were detained at U.S. borders and held for an extended period at detention centers. They all say they did not violate the terms of their authorizations nor commit any crimes. The U.S. government did not comment on why they were detained and not simply denied entry.

TIJUANA, Mexico — About 200 people in a caravan of Central American asylum seekers waited on the Mexican border with San Diego for a second st…