Gunmen killed six Egyptian soldiers as they sat in a car by a checkpoint near the Suez Canal city of Ismailia on Monday, security sources said. A car bomb also exploded outside a security building in a southern Sinai town, killing three officers and wounding almost 50 more.

The attacks highlight growing security challenges since the army ousted Islamist President Mohammed Morsi on July 3.

More than 100 policemen have been killed across Egypt in attacks since Morsi's ouster. As a result, the military has been conducting an operations in the Sinai Peninsula, east of the Suez Canal, to crack down on Islamist militants.

Monday's attacks come just one day after at least 50 people were killed in clashes between Morsi loyalists and security forces.

On Sunday, thousands gathered in Cairo's Tahrir Square to commemorate the 40th anniversary of the 1973 Arab-Israeli war. Supporters waved Egyptian flags and carried posters of the army chief General Abdel-Fattah el-Sissi, who helped remove President Morsi.

The clashes broke out when Morsi supporters attempted to converge on the square. The health ministry also reported several deaths that occured outside of Cairo in similar clashes.

Sunday was Egypt's bloodiest day since security forces raided two pro-Morsi protest camps in August, killing hundreds.

hc/tj (Reuters, AFP)