ISMAILIA, Egypt - Ten Egyptian soldiers were killed and 35 wounded in a car bomb attack near the North Sinai city of El-Arish on Wednesday, a security official said.The attack was one of the deadliest in the Sinai Peninsula, which is near Israel and the Palestinian-run Gaza Strip, since al Qaeda-inspired militants began stepping up assaults following the army's ouster of Islamist President Mohamed Mursi in July.The soldiers were traveling in a convoy on the road to the Rafah border crossing with Gaza. There was no immediate claim of responsibility.A Sinai-based militant group, Ansar Bayt al-Maqdis, said it assassinated a high-ranking security officer in Cairo on Sunday, according to a statement posted on a militant Islamist website. That group has also said it was behind a failed suicide attack on Egypt's interior minister in September.In a separate incident on Wednesday, three people were wounded in a bomb attack on a security checkpoint in Cairo, state television reported.Fears are growing that an Islamist insurgency will take hold beyond Sinai.The violence and the political struggle between Mursi's Muslim Brotherhood and the army-backed government has hit investment and tourism in Egypt, an important U.S. ally in the region.