Authorities in the northern Chinese region of Inner Mongolia have detained more than a dozen people after herders in an Evenk ethnic area staged a sit-in in protest over a grazing ban on local grasslands. Eyewitnesses said police moved in to break up the protest with force after more than 100 Evenk herders gathered with their livestock on traditional grazing lands in Hulunbuir. Photos of the aftermath of the clashes, which took place in the early hours of Friday, showed dozens of people sitting on a paved area with injuries they said were inflicted by police batons. "They have been fighting over the grasslands in Evenk banner, in Hulunbuir, Inner Mongolia," the eyewitness who supplied the photos said. "All of the different ethnic groups are starting to riot in Huiteng River," he said. Video of the standoff showed herders moving flocks and herds of sheep and cattle into the grasslands under cover of night, calling and shouting. Another clip showed protesters displaying their injuries in protest outside government offices in Hulunbuir following the clashes. Veteran ethnic Mongolian dissident Hada blamed the conflict on a rapid influx of migrant Han Chinese settlers from elsewhere in China. "This was in Yimin village," Hada said. "I heard that it was about incomers grabbing the grasslands and even stopping them from grazing their sheep and cattle." "A lot of people were beaten up and injured," he said. An employee who answered the phone at the Hulunbuir banner government offices on Friday hung up when contacted for comment by RFA. Local herder Atguuda told RFA that the problem of grasslands being occupied by internal migrants is increasingly common in the region. She accused local officials of illegally altering the household responsibility contracts under which the land is used by local people. "From a legal point of view, this is completely worthless," she said. Calls to the official she named rang unanswered during office hours on Friday. Meanwhile, a herder from Inner Mongolia's Aungsu township said she had petitioned for a number of years over the loss of grazing lands, to no avail. She called on local officials to look more closely into such disputes, which she said were a hangover from the abuses of the Cultural Revolution (1966-1976). China is home to more than 30,000 members of the Evenk ethnic group, who form one of the 56 ethnic groups officially recognized by the People's Republic of China. However, the ethnicity of the participants in Friday's protests was unconfirmed.