The homemade nail bombs caused no injuries.
"It was just one person who attacked the embassy and damaged the glass entrance with a hammer. There was no major damage and no one hurt," a spokeswoman for the German Embassy told Reuters.
The attacker was identified simply as Khaled, 54, an employee in a health unit. He threw the bomb in retaliation against offensive cartoons depicting the Prophet Mohamed which were published by a German writer, according to a statement released by the Interior Ministry.
The attacker confessed to the crime. When searched, he was found in possession of a toy plastic pistol and a piece of paper with the news story about the offensive cartoons.
Edited translation from Al-Masry Al-Youm