NAJAF (AFP) - Iraq has filed a lawsuit against private security firm Blackwater in a US court and will file another in Iraq, Prime Minister Nuri al-Maliki said on Monday, amid fury over an American court dropping charges against five Blackwater guards. The US justice department has protested against this decision, Maliki said, referring to the ruling last week to dismiss criminal charges against the guards, who were accused of killing 14 Iraqi civilians in an unprovoked attack in September 2007. For our part, we have formed a committee and filed a case against Blackwater in the United States and will file one here in Iraq, he told reporters in the holy Shia shrine city of Najaf in southern Iraq. Maliki did not give any further details about the case. Government spokesman Ali al-Dabbagh said on Friday without elaborating that Iraq had started to take the necessary measures to bring Blackwater to justice. The guards, who had been part of a convoy of armoured vehicles, had been charged with killing 14 unarmed Iraqi civilians and wounding 18 others during an unprovoked attack at a busy Baghdad roundabout using guns and grenades. Iraq says 17 people were killed. US Federal Judge Ricardo Urbina dismissed the charges against the five, saying prosecutors violated their rights by using incriminating statements they had made under immunity during a US State Department probe. The case was among the most sensational that sought to hold Blackwater employees accountable for what was seen as a culture of lawlessness and lack of accountability in the companys Iraqi operations. Blackwater pulled out of Iraq in May, after the US State Department refused to renew its contracts. The company changed its name to Xe Services last year.