U.S. Defense Secretary Leon Panetta held talks with Afghan President Hamid Karzai Thursday amid anger over the U.S. decision to fly out of Afghanistan the U.S. soldier who allegedly carried out a deadly shooting spree.

A Pentagon spokesman said the soldier was flown out of Afghanistan late Wednesday for his safety and to make him more accessible to investigators. He said the transfer did not necessarily mean his trial would not be in Afghanistan, as many Afghans have demanded.

The U.S. staff sergeant, who has not yet been named or charged, allegedly murdered 16 civilian villagers outside Kandahar province on Sunday.

In the southern city of Qalat, protesters chanted ant-American slogans Thursday, calling for justice and a public trial — in Afghanistan — for the accused U.S. soldier.

Panetta visited southern Afghanistan on Wednesday. He said the recent violence in Afghanistan — including the attack by the U.S. soldier — will not deter the U.S. from its mission in the country. While Panetta said the incident was “deeply troubling,” he said it does not reflect negatively on the behavior of NATO forces as a whole.

Around the same time Panetta arrived in Afghanistan, officials said an Afghan stole a vehicle and drove it onto a runway ramp. Officials said the driver was aiming for a group of U.S. soldiers at the airstrip for Panetta's arrival, but crashed into a ditch before emerging from the vehicle in flames. The suspect has since died from his injuries. The coalition said a NATO service member was injured in a “stolen vehicle incident.” NATO said Panetta was never in any danger.

In previous weeks, deadly Afghan protests erupted after revelations that U.S. soldiers had improperly disposed of Qurans. The dead included coalition soldiers who were killed by their Afghan counterparts. In response, NATO officials said Wednesday they are tightening the screening of Afghan forces to prevent insurgents from infiltrating the army.

Meanwhile, officials say Afghans investigating Sunday's shooting have been shown surveillance video of the accused soldier surrendering at his base. They say the footage was released in an effort to dispel rumors that more than one shooter was involved in the incident.

Afghan Defense Minister Abdul Rahim Wardak said Wednesday his government has been assured that U.S. authorities will take “appropriate action,” punishing those responsible to the “maximum extent” possible.