Sarah Buctor says Abdel Kareem Nabil was released Thursday night.
He was rounded up on Monday as he was as he was leaving Tahrir Square that is at the epicenter of the protests demanding President Hosni Mubarak's ouster since Jan. 25.
Nabil is known by his blogging name, Kareem Amer. After his March 2006 arrest, he was convicted of insulting Islam and Mubarak, and served four years in prison. After his November release, he said he will keep writing.
Nabil could not immediately be reached for comment.