A woman may need to have her arm amputated because she was so badly injured during demonstrations against the Dakota Access pipeline .

Journalist Ryan Vizzions posted graphic photos of 21-year-old Sophia Wilanskys injuries on Facebook Monday, showing her blood and exposed broken bones. He wrote that a concussion grenade hit Wilansky on Sunday night, when police used tear gas, rubber bullets and water against pipeline opponents in sub-freezing temperatures.

A concussion grenade is a type of weapon typically used in close combat, and does not explode into fragments upon detonation the way that a traditional grenade does.

A press release from the Standing Rock Medic & Healer Council corroborated Vizzions report, saying that several eye-witnesses reported that authorities were throwing concussion grenades. Fragments of some foreign material were found in Wilanskys wound, Linda Black Elk of the Medic & Healer Council told The Huffington Post.

Wayne Wilansky, Sophias father, told The Guardian that his daughter was in surgery for eight hours on Monday and said its possible her arm may need to be amputated.

The best-case scenario is no pain and 10-20 percent functionality, he said.

The young woman, who was completely conscious, saw law enforcement throw a grenade right at her, her father said at a press conference on Tuesday .

But law enforcement and former military sources none of them involved in responding to the Dakota Pipeline protests were skeptical that a concussion grenade would have caused Wilanskys injury, since they dont send off fragments and shrapnel.

A Morton County Sheriffs Department spokeswoman told the Los Angeles Times that law enforcement officers did not use concussion grenades that night and said the department was unsure how Wilansky was injured.

HuffPost was unable to reach the department.