CAIRO (AP) -- Gunmen stormed an Egyptian army checkpoint outside Cairo early Saturday morning and killed six soldiers, including some still in their beds, officials said, in what amounted to an escalation by militants on military targets near the capital.
Just days earlier, masked men opened fire on a busload of military police inside city limits, another rare attack on soldiers this far from the restive Sinai Peninsula, where the army is fighting a counter-insurgency campaign.
Provincial security chief Maj. Gen. Mahmoud Yousri told state news agency MENA that the gunmen also planted explosive devices after Saturday's attack in Shubra al-Kheima, but bomb disposal experts managed to diffuse two and detonate another in a controlled explosion.
The military blamed the Muslim Brotherhood for the attack, calling the group "terrorists" and saying they had planted the additional bombs to target rescue workers rushing to the scene.
Armed Forces Spokesman Col. Ahmed Mohammed Ali said the soldiers, of a military police unit, were attacked just after morning prayers. The Health Ministry confirmed the death toll.
"These cowardly operations will only increase our determination to continue the war against terrorism," Ali said in comments on his official Facebook page.
Amr Darrag, former head of the Foreign Relations Committee for the Brotherhood's political party, condemned the attack on his Twitter account and denied responsibility.
"How can the (Brotherhood) be accused (a) few minutes after the attack with no evidence or investigation?" he wrote.
Egyptian authorities say the Brotherhood has orchestrated a series of bomb attacks on police and other targets following the overthrow of President Mohammed Morsi, who hails from the Islamist group. This week, prosecutors referred about a dozen Brotherhood members to trial for allegedly forming an armed unit that has carried out attacks in the Nile Delta.
They have produced little evidence open to public scrutiny to bolster these claims, however, and most attacks have been claimed by the country's most active militant group, an al-Qaida-inspired organization based in the Sinai called Ansar Beit al-Maqdis, or Champions of Jerusalem. The Brotherhood denies being involved in the attacks.
Authorities in recent days have also said they arrested a number of individuals they accuse of planning attacks on the police, including a group of 12 in the Delta governorate of Menoufia and others in northern Sinai.
Separately, Champions of Jerusalem said that one of its founding leaders was killed when a bomb he was carrying was set off by a car accident.
In a statement posted on militant websites early Saturday, the group said Tawfiq Mohammed Freij died Tuesday when an accident set off a "heat bomb" he was transporting in his car. It did not say where the accident took place.
It said Freij, also known as Abu Abdullah, was one of the founders of the group, who masterminded its attacks on pipelines to stop Egyptian gas supplies from being shipped to Israel.
It called him the "field commander" of an August 2011 cross-border attack into southern Israel that targeted a bus and other vehicles near the resort city of Eilat, killing eight people. Egypt's Interior Minister identified Freij as a key figure in the extremist group in January. David Barnett, a research associate with the Washington-based Foundation for Defense of Democracies, said that Freij is the highest ranking member of the Ansar identified thus far.
The wording of the most recent statement suggests that Freij moved from either Sinai or Gaza to Cairo or elsewhere in Egypt in early 2013 to supervise the group's operations, including a failed suicide car bomb attack on the interior minister in Cairo in September 2013.
The statement could not be independently authenticated, but militant groups regularly use the websites to make announcements.
Also Saturday, a Cairo court sentenced 68 members of the Brotherhood and other youth movements to two years jail for participating in a protest without a permit. They had been arrested during protests on the third anniversary of the 2011 uprisings that led to the ouster of longtime autocrat Hosni Mubarak.
Authorities have been cracking down on Morsi supporters and other regime critics since the Islamist's overthrow last summer, saying they seek to establish law and order.
Following Saturday's attack, the National Defense Council, headed by the president and attended by military chief and other security officials, held a meeting in which members discussed security arrangements in advance of the upcoming presidential elections. They stressed the need for an atmosphere of "security and peace" to ensure a high turnout.
Meanwhile, Giza's criminal court sentenced Zohair Garana, the Mubarak-era tourism minister, to five years in jail on corruption charges. He still faces other corruption charges in a pending case.
Associated Press writer Laura Dean contributed to this report