PHOENIX (AP) — The Trump administration has begun work on a project to build a stretch of border wall in southern Arizona along part of a Native American tribe’s reservation, pushing ahead with one of its signature projects despite protests from the tribe.U.S. Customs and Border Protection says the area is a dangerous smuggling route and that building the wall will close a longstanding security gap. But members of the Tohono O’odham Nation, whose membership spans both sides of the U.S.-Mexico border, have accused the administration of trespassing and say the construction will damage land sacred to the tribe.The wall segment is part of a $46 billion dollar effort by the Trump administration to fill the border with 30-foot (9-meter) steel bollard walls, vehicle barriers, and technology designed to stop undocumented immigration and smuggling.

But as building efforts have ramped up, the administration has run into opposition from landowners, environmental groups, and Native American tribes who say construction is violating property rights and desecrating sacred indigenous sites. The Tohono O’odham Nation said in a statement Tuesday that about 20 Customs and Border Protection officers, working with contractors, went onto the tribe’s land early that morning to begin construction.Drone videos published by nation officials show roughly 14 vehicles and an industrial drill at one of the sites.