Human Rights Watch has called on Egypt to investigate allegations that its border guards killed three Sudanese migrants trying to cross into Israel.
Thousands of Sudanese refugees have crossed into Israel from Egypt
An Israeli soldier reported seeing Egyptian guards shooting one man and beating two others to death last week.
Reports in Israel say army surveillance video showed Egyptian border guards opening fire on the three refugees.
Egyptian officials have denied this and accused Israel of trying to "drive a wedge" between Egypt and Sudan.
Separately, Egyptian police last month said they had shot dead a Sudanese woman and wounded several others who were trying to reach Israel.
"The reported brutality of these killings is all the more shocking as it comes at a time when Egypt and Israel are discussing the issue of asylum seekers crossing into Israel," said Bill Frelick of Human Rights Watch, a New York-based group.
Israel estimates that 2,800 people have entered the country illegally through its border with Egypt in recent years. Most are believed to be refugees form the Darfur region of Sudan.
The number of people trying to cross into Israel has increased in recent months.
As many as 50 people arrived at the border each day in June, according to the UN High Commissioner for Refugees.