At least 30 soldiers were killed at Egyptian army checkpoints in the Sinai Peninsula by Islamic militants in a wave of simultaneous attacks, that included a suicide car bombing, security and military officials said.
The scope and intensity of the morning assaults underscored the tenacity and the resources available to the militants who have for years battled security forces in northern Sinai but stepped up their insurgency over the past two years.
The attacks took place just south of the town of Sheikh Zuweid and targeted at least six military checkpoints, the officials said.
The militants also took soldiers captive and seized weapons and several armored vehicles, they added, speaking on condition of anonymity in line with regulations.
At least 40 other soldiers were wounded, the officials said. As fighting raged, an army Apache gunship destroyed one of the armored carriers captured by the militants as they were driving it away, the officials added.
Egypt's military spokesman, Brig. Gen. Mohammed Samir, said clashes were still underway in the area between the armed forces and the militants. His statement put the number of soldiers killed so far at 10, but the conflicting numbers could not immediately be reconciled in the immediate aftermath of a major attack.
Samir's statement, posted on his official Facebook page, said some 70 militants attacked five checkpoints in northern Sinai and that Egyptian troops killed 22 off them and destroyed three all-terrain vehicles fitted with antiaircraft guns.
The officials said scores of militants were besieging Sheikh Zuweid's main police station, shelling it with mortars and rocket-propelled grenades and exchanging fire with dozens of policemen inside.
Northern Sinai has over the past two years witnessed a series of complex and successful attacks targeting Egyptian security forces, many of which have been claimed by a local affiliate of the Islamic State group.
There was no immediate claim of responsibility for Wednesday's attack, but it bore all the hallmarks of the IS affiliate.
Two of the six checkpoints were completely destroyed, one was targeted by a suicide car bombing and the second by mortars and RPGs. Army checkpoints in the area routinely have between 50 and 60 soldiers.
The attacks came just two days after the assassination in Cairo of the country's top prosecutor, Hisham Barakat, and one day after President Abdel-Fattah el-Sissi vowed to step up a two-year crackdown on militants.
Last week, Islamic State spokesman Abu Mohammed al-Adnani called in an audio message on IS followers to launch massive attacks during the Muslim holy month of Ramadan, which is now entering its third week.
Militants in northern Sinai, which borders Israel and the Gaza Strip, have battled security forces for years but stepped up their attacks following the July 2013 military ouster of Islamist President Mohammed Morsi after days of mass street protests against his rule.
El-Sissi, then the nation's army chief, led the ouster and went to become Egypt's president, winning a landslide election a year ago on a ticket that emphasized security and economic recovery.
Wednesday's attacks came in swift response to el-Sissi's pledge the previous day to carry out justice for the prosecutor general's assassination - and possibly move to execute Muslim Brotherhood leaders, an Islamist group from which Morsi hails.
Pounding his fist as he spoke on Tuesday at the funeral of Barakat, who led the prosecution and oversaw scores of cases against thousands of Islamists, el-Sissi's comments seemed to signal an even tougher campaign on the Brotherhood, Egypt's oldest Islamist group that is now outlawed and declared a terrorist organization.
Egypt has since Morsi's ouster waged a crackdown that has led to thousands of arrests, mass convictions and death sentences. Morsi is among those condemned to die, but has a potentially lengthy appeal process ahead of him.
El-Sissi said the government was ready to brush aside criticisms and free the judiciary's hand for a "battle" the country is prepared to wage.
"The judiciary is restricted by laws, and swift justice is also restricted by laws. We will not wait for that," el-Sissi said.
Action will be taken within days "to enable us to execute the law, and bring justice as soon as possible," he said. "We will stand in the face of the whole world, and fight the whole world."
In a thinly veiled reference to jailed members of the Brotherhood, el-Sissi blamed the violence on those "issuing orders from behind bars," and warned: "If there is a death sentence, it will be carried out."