Authorities had arrested 141 people who were protesting a controversial North Dakota oil pipeline early on Friday, NBC News reported.
The arrests came after a more than six-hour standoff over the stretch of private land lying in pipeline's path, the Morton County Sheriff's Department said in a statement.
Demonstrators blockaded roads and bridges by setting fire to bales of hay and construction equipment. The sheriff's department said at least seven protesters used "sleeping dragon" devices, which typically involve PVC or other pipe, to physically latch themselves onto vehicles and large concrete. According to police, some protesters threw rocks and improvised fire bombs as law enforcement officers closed in.
Police forces responded by using pepper spray and firing bean bags on protesters.