Doctors testified protesters in Kasserine and Thala in west-central Tunisia were shot from behind, indicating they were fleeing, said the London-based rights organization, which had a delegation in Tunisia from Jan. 14 until Saturday.
Other protesters in Tunis, as well as in Kasserine, Thala and Regueb in central Tunisia, were killed by single shots to the chest or head, "suggesting deliberate intent to kill," Amnesty International said.
"This shocking evidence confirms that the Tunisian security forces were using lethal methods to quell discontent and to deter protesters," Hassiba Hadj Sahraoui, Amnesty International's Middle East and North Africa deputy director, said.
"The fact that some of those killed were clearly running away shows flagrant disregard for the people's lives," Hadj Sahraoui said. "It must be an urgent priority for the authorities to ensure that those under their command show restraint and respect for public safety."
Tunisia's sudden and explosive wave of street protests began in December and led to the ouster of President Zine el-Abidine Ben Ali Jan. 14 after 23 years of rule. There was protester violence, but security forces used disproportionate force, firing tear gas, rubber bullets and live ammunition even when protesters were peaceful, the group said.
The demonstrations and riots, which became known as the Jasmine Revolution, were reported to have started over unemployment, food inflation, corruption, freedom of speech and poor living conditions.
The government said 78 protesters died and 94 were injured in the demonstrations.