The private security company Blackwater USA has been involved in more shootings while guarding US diplomats in Iraq than other security contractors operating in the same strife-torn country, a report published Thursday by The New York Times revealed.

Blackwater is currently under investigation in Iraq and the United States after some of its employees were involved in a shootout on September 16 that left behind at least 11 people dead in Baghdad.

The New York Times quoted government officials and other persons familiar with the State Department reports as saying Blackwater personnel have an 'itchy trigger finger' and opened fire in numerous situations. The number of such incidents far surpasses that of two other US companies, DynCorp International and Triple Canopy.

The State Department registers every incident during which security guards open fire while protecting diplomats, but the reports aren’t made public.

Earlier this month, Blackwater personnel began firing at alleged militants after a diplomatic convoy they were guarding was attacked in western Baghdad. But the Iraqi authorities said only innocent civilians were killed and suspended the company’s licence, launching an inquiry.

“They started shooting randomly from four positions in the square, killing 11 civilians and injuring 12 others. The first one who was killed was a driver who failed to stop and then his wife,” Interior Ministry spokesman Maj. Gen. Abdul-Karim Khalaf said after the shooting.

US President George W Bush announced last week that US and Iraqi experts will investigate the incident and people found responsible will be brought to justice. A team of US investigators was sent to Iraq, while the Baghdad government launched a thorough investigation in the company’s activities.

The North Carolina-based firm and other similar companies provide security for US diplomats, politicians and Iraqi companies, but the security guards have been often criticized for their actions. Many said some of them are not properly trained and act rashly in limit situations.

Most of the employees are former US military special operations soldiers, trained to secure convoys and handle small rapid fire situations, but critics said Blackwater employees take violent actions to protect the people or assets they are paid to guard.

Meanwhile, Blackwater resumed work last week after US embassy officials and the Iraqi administration analyzed the option over the past days. The private security company will be involved in limited operations outside the heavily-guarded Green Zone in Baghdad until the inquiry is complete.