The protestors, who also fired shots, blocked entries to the mine, the company's railroad and offices. The company said in a statement they also entered the mines and looted equipment and building materials near the mine entrance, causing significant damage.
One demonstrator, who declined to be named, said ArcelorMittal had not fulfilled the terms of its concession agreement with the Liberian governmenOt. The person added that the company had not compensated local people for crops, nor had it paid wages or renovated houses.
The Indian steel and mining conglomerate operates the plant in Nimba County under a 25-year deal with the government.
"Ringleaders, including those who shot at the police, have been arrested and are being brought to Monrovia for further investigation and prosecution," the presidency said in a statement.
The statement assured investors that the government would protect their lives and property. It said police had restored calm to the city of Yekepa where the mine is situated, following the protest, which began on Thursday.
The West African state is recovering after a long civil war that ended in 2003. ArcelorMittal, BHP and other companies have moved into the country to tap iron ore reserves.