This comes after US lawmakers voiced concern over the growing popularity of the Islamic group among the Egyptian public.
Abdul Jalil el-Sharnouby editor of Ikhwan online site says that the social networking service has given no reason for the partial blocking.
He added that the move is part of Islamophobia and anti-Islamic agenda pursued by US officials in various parts of the world.
The Muslim Brotherhood has launched an active online campaign to inform the youth about the Islamic Awakening in the Middle East and North Africa.
Sharnouby added that Washington opposes the Islamic intellectual movements, while welcoming the presence of al-Qaeda terrorists in cyberspace.
The developments come two month after a popular revolution toppled US-backed former Egyptian dictator Hosni Mubarak and his associates in the region.
Senior officials in Washington fear that the Muslim Brotherhood will play a crucial role in the future democratic government and can endanger the illegitimate interests of the US and Israel in the region. Agencies