Story highlights Mohamed Badie is arrested at an apartment in the Nasr City section of Cairo

25 soldiers die in an attack in the Sinai Peninsula; 3-day mourning period declared

At least 37 Muslim Brotherhood prisoners reportedly killed in jailbreak attempt

Former President Hosni Mubarak is acquitted in one of many cases against him

Egyptian security forces arrested Mohamed Badie, the Muslim Brotherhood's spiritual leader, at a residential apartment in Cairo on Tuesday, state-run Nile TV reported.

He was arrested in the Nasr City section of the capital without any resistance, Nile TV said, citing Gen. Abdel Fattah Othman, an Interior Ministry spokesman.

Badie, whose title is supreme guide, is accused of inciting violence, according to Nile TV. The Brotherhood picked a Badie deputy to temporarily replace him, its political wing said Tuesday. He is Mahmoud Ezzat.

Badie's detention came one day after 25 soldiers were killed in a Sinai ambush and onetime ruler Hosni Mubarak won acquittal on a corruption charge.

Suspected militants armed with rocket-propelled grenades struck two buses carrying security forces and killed the soldiers in the city of Rafah, on the border between Egypt and Gaza, Nile TV reported.

Photos: Photos: Egypt protests Photos: Photos: Egypt protests Photos: Egypt protests – Protesters and Egyptian riot police clash in Cairo on January 17, as the country awaits the results of a constitutional referendum. On January 18, the electoral commission announced the constitution had overwhelmingly been approved. Hide Caption 1 of 20 Photos: Photos: Egypt protests Photos: Egypt protests – An Egyptian youth holds up his national flag outside a polling station in Cairo on January 14, day one of a two-day vote on a new constitution. Hide Caption 2 of 20 Photos: Photos: Egypt protests Photos: Egypt protests – On December 25, 2013, The Egyptian interim government declared the Mohammed Morsy-led Muslim Brotherhood a terrorist organization. The action was taken in response to a police station bombing in Mansoura, which the government has stated was the responsibility of the Brotherhood, despite denials from the group itself. Hide Caption 3 of 20 Photos: Photos: Egypt protests Photos: Egypt protests – Cairo University's students backing ousted Islamist president Mohamed Morsy flash the four-finger sign during a demonstration against July's military "coup " in Tahrir square on December 1, 2013. The four-finger sign has become associated with a government crackdown on pro-Morsy supporters in Cairo's Rabaa al-Adawiya square on August 14. Hide Caption 4 of 20 Photos: Photos: Egypt protests Photos: Egypt protests – Egyptian women members of the Muslim Brotherhood hold roses as they stand in the defendants' cage dressed in prison issue white during their trial in at the court in the Egyptian Mediterranean city of Alexandria on December 7, 2013. Hide Caption 5 of 20 Photos: Photos: Egypt protests Photos: Egypt protests – Egyptian protesters use flare lights at Talaat Harb Square in downtown Cairo on November 26, 2013 during a clash with police after the security forces dispersed protesters from a demonstration organized by human rights group "No Military Trials for Civilians" in the first unauthorized protest staged in the capital since the adoption of a law that regulates demonstrations. Hide Caption 6 of 20 Photos: Photos: Egypt protests Egypt protests – A soldier sets up barbed wire in anticipation of protesters outside the constitutional court in Cairo on Sunday, August 18, 2013. During the previous week about 900 people -- security forces as well as citizens -- had been killed. Deaths occurred when the military used force to clear supporters of ousted president Mohamed Morsy from two sit-in sites in Cairo, and violence raged after Morsy supporters staged demonstrations. Hide Caption 7 of 20 Photos: Photos: Egypt protests Egypt protests – Friends and relatives of Ammar Badie, 38, killed during clashes in Ramses Square, carry his coffin during his funeral in Al-Hamed mosque in Cairo on August 18, 2013. Ammar Badie was the son of the Muslim Brotherhood's spiritual leader, Mohammed Badie. Hide Caption 8 of 20 Photos: Photos: Egypt protests Egypt protests – Wreckage and debris litter the area around the Al-Fateh mosque in Cairo, where hundreds of Islamist protesters had barricaded themselves on Saturday, August 17, 2013. Thousands defied an emergency order by taking to the streets the day before to mark a "Friday of anger" in support of ousted president Mohamed Morsy. Hide Caption 9 of 20 Photos: Photos: Egypt protests Egypt protests – Policemen stand guard inside a room of Al-Fateh mosque as supporters of ousted president Mohamed Morsy exchange gunfire with security forces inside the mosque in Cairo on Saturday, August 17, 2013. Hide Caption 10 of 20 Photos: Photos: Egypt protests Egypt protests – Members of the Muslim Brotherhood and Mohamed Morsy supporters flee shooting near Ramses Square in Cairo on August 16, 2013. Hide Caption 11 of 20 Photos: Photos: Egypt protests Egypt protests – Egyptian soldiers take positions alongside armored vehicles as they guard the entrance to Tahrir Square in Cairo on Friday, August 16, 2013. Hide Caption 12 of 20 Photos: Photos: Egypt protests Egypt protests – A man on checks out a list of names of those killed in the crackdown on, on August 15, 2013. Hide Caption 13 of 20 Photos: Photos: Egypt protests Egypt protests – A man walks inside the burned-out Rabaa Al-Adawiya mosque in Cairo on August 15, 2013. Hide Caption 14 of 20 Photos: Photos: Egypt protests Photos: Egypt protests – Mohamed Morsy masks are displayed for sale at the base for supporters of the ousted president on July 12, 2013 in Cairo, Egypt. The country has been in a state of political paralysis following the ousting of former president and Muslim Brotherhood leader Morsy by the military. Hide Caption 15 of 20 Photos: Photos: Egypt protests Photos: Egypt protests – Two veiled Egyptian women, supporters of Mohamed Morsy, sit in front of police standing behind barbed wire fencing that blocks the access to the headquarters of the Republican Guard in Cairo on July 8, 2013. Hide Caption 16 of 20 Photos: Photos: Egypt protests Egypt protests – A woman tries to stop a military bulldozer from hurting a wounded youth during clashes on August 14, 2013, in eastern Cairo. Hide Caption 17 of 20 Photos: Photos: Egypt protests Egypt protests – Supporters of ousted president Mohamed Morsy run as Egyptian security forces fire toward them on August 14, 2013. Hide Caption 18 of 20 Photos: Photos: Egypt protests Egypt protests – The national identity cards of protesters allegedly killed during a clear-out operation by Egyptian security forces on pro-Morsy demonstrators are exchanged at the Rabaa al-Adawiya Medical Center on August 14, 2013. Hide Caption 19 of 20 Photos: Photos: Egypt protests Egypt protests – Egyptian security forces detain protesters in Cairo's Nasr City district on August 14, 2013. Hide Caption 20 of 20

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Interim President Adly Mansour declared three days of national mourning following the attack, Nile TV said.

The Sinai Peninsula is a lawless area that was the site of frequent attacks even before Egypt's latest round of turmoil. In May, for example, seven Egyptian solders were kidnapped and held for six days there, a spokesman for Egypt's armed forces said.

But the attack adds to the persistent tension across the country since the military ousted democratically elected President Mohamed Morsy in a coup.

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Over the past week, about 900 people -- security personnel as well as citizens -- have been killed.

Deaths occurred when the military used force to clear two pro-Morsy sit-in sites in Cairo on Wednesday and violence raged after pro-Morsy supporters staged demonstrations Friday.

On Sunday, at least 37 jailed members of the Muslim Brotherhood, an Islamist movement, were reportedly killed in what the Interior Ministry called an attempted jailbreak.

Egypt's state-run EGYNews agency reported that the prisoners died from tear-gas suffocation and from trampling over each other, and Egypt's Prosecutor General Office ordered the arrest Monday of two police officers for their involvement in the incident. The prosecutor general also ordered that three police officers hospitalized for injuries sustained in the incident be held while the investigation continues.

As for the Sinai ambush, the Brotherhood condemned the attack on Egyptian soldiers.

"Our peaceful protests (are) stronger than any weapon, and we don't accept any violence," said Murad Mohamad Ali, media adviser to the Brotherhood's Freedom and Justice Party.

Morsy supporters, many of whom are members of the Muslim Brotherhood, and those aligned with the military-backed interim government blame each other for stoking the violence.

Morsy has been in detention since his overthrow. Egyptian prosecutors have extended the detention for 15 days, pending investigations.

Prosecutors have charged him with participating in the detention, torture, murder and attempted murder of Egyptian citizens; broadcasting false news to influence judicial authorities in their inquiries; and inciting thugs to use force and terrorize citizens.

Questions about aid

The crackdown also spurred a call from a leading U.S. senator, John McCain, to cut off its $1.3 billion in aid to Egypt. He said the United States has failed to follow its own rule requiring suspending aid to states overtaken by a military coup -- though the United States has not officially described the recent regime change in Egypt as a coup.

"We have no credibility. We do have influence, but when you don't use that influence, then you do not have that influence," McCain said Sunday on CNN's "State of the Union."

U.S. Defense Secretary Chuck Hagel said President Obama noted that "every aspect" of the U.S.-Egypt relationship is under review.

He said the U.S. message to Egyptian officials has been consistent: The interim government should "get back to an inclusive approach to reconciliation in Egypt.

Will the regime get the message? The U.S. ability to influence events in Egypt is "limited," Hagel said, but it's not "without influence."

Speaking at a Pentagon briefing with his counterpart from China, Hagel said the United States has a longstanding relationship with Egypt.

"We have interests clearly in the Middle East -- interests that include hopefully a development of some progress toward an Israeli -Palestinian settlement. So we continue to work with the Egyptian interim government as well as the Egyptian military," he said.

Hagel also said protection of Americans in Egypt is of the "highest priority."

But Saudi Arabia's foreign minister assured Egyptians that Arab nations will support Egypt if any international aid to the country is cut, the Saudi Press Agency reported Monday.

"The Arab and Islamic nation is rich when it comes to the support of its sons and its potentials and will not shy away from providing a helping hand to Egypt," Saud Al-Faisal said.

International response called weak, ineffective

The carnage has spurred a call from leading human rights group Amnesty International for a "full, impartial and effective investigation in the shocking loss of life."

"The interim government has already stained its human rights record -- first by breaking its promises to use nonlethal weapons to disperse pro-Morsi sit-ins and allow for the safe exit of wounded, and then by justifying their actions despite the tragic loss of lives," said Salil Shetty, secretary-general of Amnesty International, in a news release.

"The response of the international community has been weak and ineffective, even as everyone leaps to condemn the horrific loss of life. The international community must act decisively to send a message that no government can behave this way and retain any credibility."

The group documented a rise in civil strife since the July 3 coup and cited "a string of serious human rights abuses, culminating in the wholesale attack by the security forces" on pro-Morsy sit-ins last week.

"These abuses have included an alarming and unprecedented rise in sectarian violence against Coptic Christians across the country, "seemingly in retaliation for their support" for Morsy's ouster.

It cited abuses by pro-Morsy protesters "including beatings, torture and killings.

"In recent days, the scale of violence by some Morsy supporters have manifestly increased, as some attacked government buildings and police stations and personnel. Some protesters have also fired live ammunition on local residents," Amnesty said.

Mubarak in court

As the upheaval persists in Egypt, Mubarak's court cases grind on. In Cairo, a criminal court acquitted the former president in a corruption case, Egyptian state TV reported Monday.

The case stemmed from accusations of squandering public money allocated for renovating presidential palaces. He also faces at least one other outstanding corruption claim.

Separately, Mubarak is also facing a more serious accusation: that he was involved in the killing of protesters during the 2011 uprising.

A Cairo court on Saturday adjourned a retrial in that case to this coming Sunday.

Mubarak ruled Egypt, the most populous Arab country, for three decades until demonstrators opposing his rule forced his ouster in 2011. He was convicted in 2012 in the deaths of numerous protesters, but was later granted a retrial.

After a lengthy trial, he and his former interior minister, Habib al-Adly, were found guilty and sentenced to life in prison last year on charges that they were complicit in the protesters' killings. After appealing their convictions, they were granted a new trial early this year.

Mubarak has been held since his guilty verdict last year. After months spent in a military hospital, a public prosecutor sent him back to prison in April.

The ousted autocratic leader's health has been a bone of contention during his trial and incarceration. He suffered a heart attack after relinquishing power and had said that he was physically unfit to stand trial.