Gunmen killed a police officer Friday in northern Egypt who worked as a guard for a judge hearing a case against the country's ousted president as his supporters held scattered demonstrations that saw one person killed, authorities said.

The police officer had been riding a motorcycle in the Nile Delta city of Mansoura when gunmen on another motorbike opened fire on him, the Interior Ministry said in a statement on its official Facebook page.

A security official said the slain officer guarded a judge in one of four trials facing toppled Islamist President Mohammed Morsi. The official said the officer was killed on his way from the judge's home.

Officials also said they dismantled a homemade bomb on a main bridge in the north of Cairo.

A series of bombings and targeted killings, mainly striking security forces and installations, have hit the country since the military overthrow of Morsi in July.

(Author not mentioned, ABC News, Mar. 9, 2014) Read original