CAIRO -- Machine gun-wielding assailants fired Friday on an Egyptian military armored personnel carrier on the road linking the capital and the Suez Canal city of Ismalia, killing two soldiers and wounding two others, state media reported. The army for the past month has been in the midst of a major offensive against Islamist militants in the Sinai Peninsula, but some clashes have occurred closer to the capital, including fighting last month in towns in the Nile Valley and on the outskirts of Cairo. In the wake of Friday's early-morning shooting, troops backed by helicopters swarmed villages near the scene. The official MENA news agency said two of the assailants were captured and that about half a dozen others were being sought. A military coup largely backed by the public drove Islamist president Mohamed Morsi from power three months ago. In the intervening months, security forces have taken a hard line against his supporters in the Muslim Brotherhood and other Islamist groups. Hundreds of Morsi's backers were killed in a violent crackdown on protests in mid-August. The Brotherhood is now legally banned, and authorities are moving to seize its assets and shut down affiliated organizations. Most of its leadership is in jail, along with thousands of rank-and-file members of the group, but Morsi's supporters have been staging rallies calling for his reinstatement. Scattered protests by the ousted president's partisans took place Friday at several locations in Cairo, with police firing tear gas to drive some demonstrators back. Troops and tanks sealed off Tahrir Square, the iconic site of enormous protests that forced longtime autocrat Hosni Mubarak from power in 2011. Islamists had held a small protest in the square earlier this week, and have vowed to stage more. The capital braced for potential clashes on Sunday, when the army will mark the anniversary of its initial successful strike against Israel during the 1973 war in the Middle East. The Brotherhood has promised large-scale counter-demonstrations. President Obama cancels trip to Southeast Asia