Others had injuries they had sustained while fleeing their homes in Myanmar's Rakhine State.
"Security forces surround a village, shoot people fleeing in panic and then torch houses to the ground", said Tirana Hassan, Amnesty's crisis response director.
UN Secretary-General Antonio Guterres and the UN Security Council have urged Myanmar to end the violence, which he said was best described as ethnic cleansing.
Among the hundreds of thousands of Rohingya refugees pouring across the border into Bangladesh, stories of murder, rape and devastation are common.
Suu Kyi is not Myanmar's president - her official titles are state counselor and foreign minister - but she effectively serves as leader of the Southeast Asian nation though she does not control the military.
The migration of Rohingyas to south-eastern Bangladesh had steadily increased since the attacks on police and military posts by an insurgent group and Myanmar's subsequent military crackdown.
But the position effectively makes her Myanmar's de facto leader.
Rex Tillerson, in a meeting with Boris Johnson, says the conflict in Myanmar must stop.
"We are urgently appealing for more funds (for assistance)", he said.
Guterres repeated his call for "an effective action plan" to address the root causes of the situation, which he said had been left to fester for decades and has now escalated beyond Myanmar's borders, destabilizing the region.
The Rohungya Muslims are fleeing their country to avoid the national military's who started killing innocent civilians and burning Rohingya villages after a militant attack on the security force's camp on August 25.
Critics have called for the Nobel laureate to be stripped of her peace prize amid reports of "ethnic cleansing" against Rohingya Muslimse.
The exodus of refugees, sparked by the security forces' fierce response to a series of Rohingya militant attacks, is the biggest problem Suu Kyi has faced since taking charge past year.
When asked at a press conference in NY whether he would describe the violence against Rohingya Muslims as "ethnic cleansing", he replied: "When one-third of the Rohingya population has got to flee the country, can you find a better word to describe it?"