Seven Egyptians were shot in the head in Libya, a security official said.
The men, who could have been merchants, were found dead on a beach in Libya and might have been victims of a robbery. They had no possessions with them.
Reports speculate the men may have been abducted from their apartments. According to local residents, the gunmen were going door to door asking if residents were Christian or Muslim. The men were thought to have been Christian.
A Libyan ministry official told the BBC's Rana Jawad that authorities could not "at this stage speculate on the motive of the crime.”
"Egypt expects from the Libyan side a speedy investigation into this gruesome crime ... to provide results as soon as possible and a prosecution of the culprits," a spokesman said.
In January, a British man and New Zealand woman were also shot execution-style on another beach near Libya.
Over the past year and a half, assassinations, car bombings and kidnappings have become more common in Benghazi. Those acts are thought to be by the Islamist extremist groups.
The Islamist group Ansar al-Sharia is active in the east of Libya, according to Reuters.
The violence comes after a revolution ousted Moammar Gadhafi.