The US soldier accused of killing 16 Afghan villagers was upset by a serious injury sustained by an army comrade the day before the massacre, but held no animosity toward Muslims, his lawyer has said.

The 38-year-old army sergeant, being held in Kuwait, was also unhappy about being sent to Afghanistan, having earlier been told he would not be redeployed after three tours in Iraq, according to his Seattle-based civilian attorney.

The soldier and his family have moved to a military base south of Seattle because of security fears and concerns about possible retaliation for the attack.