Police briefly detained eight members of the outlawed Muslim Brotherhood on Saturday when some of the men tried to register as candidates in national trade union elections, the group said.
Five were arrested in Cairo and three others were detained in the northern Nile Delta province of Menoufiya, officials from the group said. They were held for several hours and then released, the officials said.
"The arrests cannot be justified," said Abdel-Moneim Abdel-Maksoud, a lawyer for the group. "This is one of the government's ways to prevent the group's members from having any official representation in any official organization."