The group's official website also said police had raided stores owned by Brotherhood supporters in the province of Fayoum south of Cairo.
The Muslim Brotherhood operates openly despite an official ban since 1954.
Members running as independents won nearly one fifth of the seats in the influential lower house of the parliament in 2005.
The government says the organisation is illegal and regularly arrest its members.
The Brotherhood said it had registered 19 candidates for the June 11 elections elections.
Egyptians have largely ignored the Shoura Council polls in the past, but the next ballot will be the first since changes to the constitution gave some legislative powers to the house.
Analysts say the government wants to stop the Brotherhood now before it makes more electoral gains that could help it mount a serious threat to the rule of Hosni Mubarak, the Egyptian president, in power since 1981.