CAIRO - An explosion on Sunday near the Cairo's Coptic cathedral killed at least five people and injured 10, Egyptian security sources said.There was no immediate claim of responsibility.On Friday, two roadside bombs - one in Cairo and one north of the capital - killed six policemen and wounded six others.The blast came just one day after two car bombs outside of an Istanbul soccer stadium left over 30 people dead and wounded more than 150.Jpost.com staff contributed to this article.