An Iraqi government investigation has found that hunting rifles were used against anti-government protesters that led to the killing of at least three people this week. “The investigation found that the protesters were killed by pellets from personal hunting rifles, fired by three members of the security forces,” Interior Minister Othman Al Ghanimi said on Thursday.. The minister said an arrest warrant was issued for the three members and the matter will be left with the judiciary. Power shortages and poor public services, a common occurrence since 2003, led to the latest street protests as people struggled to keep cool amid the surging heat. The protests began on Sunday night in Baghdad and several southern cities, and turned violent in the capital. Earlier this week, the Interior Ministry said in a report that "security services have monitored dangerous criminal groups seeking to create chaos" during the demonstrations. "Their mission is to trigger security forces to attack demonstrators by starting conflict with them," said the report. The ministry urged protesters to “co-operate” with security forces to identify the "criminal groups". Military spokesman Yehya Rasool said in a statement earlier this week that security forces were given strict instructions not to use force against protesters. Earlier on Thursday, the government said that approximately 560 Iraqi protesters and security forces were killed in months of anti-government unrest that erupted last October. The protests unseated former prime minister Adel Abdul Mahdi, who resigned in November but continued to hold the post in caretaker role. The new government of Prime Minister Mustafa Al Kadhimi, who took office in May, has pledged to investigate the deaths and imprisonment of hundreds of protesters. The death toll is roughly in line with what news outlets and rights groups have reported. “The government will treat all 560 people as martyrs and each family will be offered 10 million dinars [Dh31,000] in compensation,” Hisham Daoud, adviser to the prime minister, said. Mr Al Kadhimi made a surprise visit to the central investigation prison in Al Muthanna airport, Baghdad, on Wednesday night. The visit was to check on “the status of prisoners and to ensure that there weren’t any protesters or prisoners of conscience,” said a government statement. The Iraqi army said on Thursday night that two rockets targeted Baghdad airport, where US soldiers are posted, adding there were no casualties. It was the 39th attack targeting US interests since October in Iraq, a country where the US and its rival Iran vie for influence. As with previous attacks, the rocket fire went unclaimed. The US has routinely blamed pro-Iran factions for targeting its interests in Iraq in recent months.