"Because these people, innocent people, the children, women, they are suffering".
She condemned the attacks by insurgents on the Myanmar border police and the military.
The OIC meeting called upon the government of Myanmar to accept the UN Human Rights Council's fact-finding mission to conduct a thorough and independent investigation into all alleged violations of global human rights law and to bring the perpetrators to justice.
The government of the Buddhist-majority country says its security forces are fighting Rohingya militants behind a surge of violence and they are doing all they can to avoid harming civilians.
In an address to the United Nations human rights council in Geneva, Zeid Ra'ad Al Hussein denounced the "brutal security operation" against the Rohingya in Rakhine state, which he said was "clearly disproportionate" to insurgent attacks carried out last month.
Korea denounces new United Nations sanctions
North Korea was condemned globally for its latest nuclear test on September 3, which it said was of an advanced hydrogen bomb. The North says it needs nuclear arms to protect itself, but the United States has accused the country of "begging for war".
Mogherini said in another statement released on Monday that the European Union is "stepping up our humanitarian engagement" in Bangladesh.
So far, neighboring Bangladesh has opened up its borders to the fleeing Rohingya and are set to host hundreds of thousands more.
Suu Kyi has not spoken out against what the United Nations is calling ethnic cleansing, which has incited outrage from the worldwide community and calls for her Nobel Prize to be revoked. "Myanmar has created the problem and they will have to solve it", the Prime Minister said.
She reiterated her called to the global community to mount pressure on the Myanmar government so that its army stop the atrocity, they take the Rohingya back to their home and treat as Myanmar citizen with all the rights they are entitled.
Three Rohingya are reported to have been killed by a mine, and at least two more have lost limbs.
It is still not clear who is responsible for the placing of landmines, or when they were laid, but the issue raises uncomfortable questions for the Myanmar government.
Mr Zeid, the United Nations High Commissioner for Human Rights, said the current operation in Rakhine was "clearly disproportionate".