The U.S. soldier who allegedly carried out a deadly shooting spree in Afghanistan has been flown out of the country.

An unidentified senior U.S. official said the soldier was flown late Wednesday to Kuwait, where the U.S. military has several detention facilities.

A Pentagon spokesman said the soldier was being flown out of Afghanistan 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.

U.S. Defense Secretary Leon Panetta, who visited southern Afghanistan on Wednesday, said 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.

“None of this is reflective of the overwhelming majority of troops – ISAF troops, Afghan troops — who day to day are doing the job of trying to protect this country, and doing it in outstanding fashion with courage and dedication.”

Around the same time Panetta arrived in Afghanistan, officials said an Afghan stole a vehicle and drove it onto a runway ramp, crashing 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.

Panetta's visit follows weeks of deadly Afghan protests that 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.

In violence Wednesday, a roadside bomb killed eight civilians in Helmand province. Earlier, in neighboring Kandahar province, a motorcycle bomb killed one Afghan security officer and wounded at least two other people.

Afghan President Hamid Karzai and the U.S. embassy in Kabul condemned the violence.

No one has claimed responsibility for the attacks, but the Taliban had vowed to avenge the recent murder of Afghan civilians. On Tuesday, Taliban militants opened fire on a memorial service for the 16 slain villagers in Kandahar, killing an Afghan soldier and wounding a policeman.