CAIRO (AP) -- Egyptian authorities on Wednesday continued their crackdown on the Muslim Brotherhood and its allies by arresting two more high-profile Islamist figures, while officials said that they had started a closed hearing in a prison outside Cairo on whether to release jailed ex-president Hosni Mubarak.

The arrested Islamists include a preacher known for his fiery sermons who was reportedly caught as he tried to flee to neighboring Libya in disguise, and a spokesman for the Brotherhood said to be on his way to catch a flight out of the country.

They are the latest allies of President Mohammed Morsi, who hails from the Brotherhood, to be arrested. On Tuesday authorities detained the Brotherhood's supreme leader and spiritual guide, Mohammed Badie, dealing a serious blow to an embattled movement now struggling to keep up its protest campaign against the military's overthrow of Morsi and subsequent deadly assaults on pro-Morsi sit-ins.

Security officials meanwhile said that a court was conducting hearings in Tora prison near Cairo over whether or not Mubarak could be released.

A court ruling earlier in the week raised the possibility that Mubarak could walk free, a move that would fuel the unrest roiling the country after the autocratic leader's successor was removed in a military coup.

Mubarak, in detention since April 2011, was found guilty and sentenced to life in prison last year for failing to stop the killing of some 900 protesters in Egypt's 2011 uprising. His sentence was overturned on appeal and he is now being retried, along with his security chief and six top police commanders. He is facing a number of other corruption charges.

Judicial officials have ordered Mubarak's release pending trials. His lawyers argue that he should be let go after Wednesday's hearing into charges of having received gifts from the state-owned Al-Ahram newspaper _ the last case that has kept him in detention.

Many analysts have expressed skepticism that he would be let out, saying the political cost of freeing the former leader, who was widely hated for widespread abuses and repression during his 29 years in power, could keep him in jail.

Meanwhile, in a late night Tuesday statement, the Brotherhood and the allied Anti-Coup Coalition appealed to their supporters to continue street demonstrations in their neighborhoods and to stay home from work.

"The detentions and terror operations carried out by coup-makers should not demoralize you," the statement said. "It is your duty to continue daily activities undeterred."

Hundreds, including the group's former lawmakers, politicians, and field organizers are already in custody.

Badie was arrested Tuesday in an apartment in the Cairo district of Nasr City, close to the site of a sit-in encampment that was forcibly cleared by security forces last week, triggering violence that killed hundreds of people.

Morsi and his top aides have been held incommunicado at unknown locations since the July 3 military coup. The ouster of Morsi, Egypt's first democratically elected president, came after four days of mass protests in Cairo and elsewhere demanding he step down for abusing his power.

On Wednesday, cleric Safwat Hegazy, a fiery preacher from the ultraconservative Salafi movement and a top Brotherhood ally, was captured at a checkpoint near the Siwa Oasis in eastern Egypt and close to the border with Libya, according to the state-run MENA news agency. The cleric is wanted on charges of instigating violence.

According to the website of the state-run Al-Ahram daily, Hegazy had shaved off most of his beard, dyed his hair and covered his face with a niqab, a head-to-toe woman's dress that leaves only a slit for the eyes uncovered.

But the head of local security where Hegazy was arrested denied he was disguised as a woman, saying the cleric had dramatically changed his looks, shaving his trademark white beard, dying it black and keeping only a black goatee, and dressing as a local Bedouin. Maj. Gen. Enani Hamouda was speaking to the privately owned Al-Hayat TV.

Egyptian state TV aired a photo showing him sitting next to army soldiers, clean-shaven and dressed in a white robe, without his prescription glasses and flashing a smile.

MENA said Hegazy, who joined ranks with the Muslim Brotherhood in campaigning for Morsi's presidential bid, showed no resistance during his arrest and was flown to a detention center in Cairo.

Hegazy was a key speaker at the main pro-Morsi sit-in that was dispersed by security troops last week in Cairo's Nasr City suburb. He told protesters to hold their ground and promised to deal blows to the military. He is wanted on charges of instigating deadly clashes last month with security forces outside a Republican Guard building that killed 54 people, most of them Morsi supporters.

Also, an Egyptian security official said Mourad Ali, a spokesman for the Brotherhood's political party, was detained at Cairo airport while trying to catch a flight to Italy. The official said Ali's name was on the watch list in the airport for his involvement in the latest violence in Egypt. The official didn't elaborate.

All officials spoke on condition of anonymity because they were not authorized to talk to the media.

The Brotherhood arrests appear aimed at crippling the group and weakening its ability to continue putting pressure on the government.

Over the past three days, the group's campaign of near-daily protests has petered out, with scattered demonstrations in Cairo and elsewhere attracting mere hundreds, or even dozens, of protesters.

On Tuesday, several hundred Morsi supporters staged protests in Helwan, an industrial suburb south of Cairo, and in Ein Shams, a residential district on the opposite end of the city, shortly before the 11-hour curfew went into effect at 7 p.m. They also held a similar rally in the southern suburb of Maadi.

Key Brotherhood figures who are still on the run and wanted for various charges are Mohammed el-Beltagy, a former lawmaker and a member of the assembly that last year drafted the now-suspended constitution, and Essam el-Erian, deputy leader of the Freedom and Justice party, the political arm of the group.

In an opinion piece published in the British daily the Guardian, el-Beltagy said the authorities' crackdown on his group and its allies amounts to crimes against humanity, and called on the Egyptian security forces to desert.

He dismissed claims that his group is carrying out terrorist acts, accusing Gulf nations, the United States and Israel and other Western countries of aiding the military and its allies "to kill the Egyptian dream and undermine the Arab Spring."

"Those who willingly or knowingly participate in this project are hereby warned that they will one day, sooner or later, be brought to justice," he wrote. "I appeal to army and police officers and soldiers to rid themselves of the military uniform and go home."