An Egyptian-American journalist says the beating she suffered at the hands of riot police in Cairo is exactly the kind of abusive power that protesters are fighting to wipe out in Egypt.

Mona Eltahawy, 44, was observing the fighting between protesters and security forces in Tahrir Square overnight, when she became surrounded by a group of riot police officers.

"They hit me with their sticks on the arms and head. They sexually assaulted me, groping my breasts and putting their hands between my legs," she told The Associated Press. "For a moment I said, 'This is it. No one is around. I am finished."'

She shouted: "No! No," as she struggled and her attackers dragged her by the hair from the street to the Interior Ministry, cursing her.

Her left arm and right hand were broken as a result of the attack.

Eltahawy lives in New York and is a prominent women's rights defender and lecturer on social media in the Arab world. She has visited Egypt at least twice since the January uprising.

Eltahawy first told her story through Twitter, describing the details of her nightmare to thousands of followers.

Security forces beat her, groped her and subjected her to "the worst sexual assault ever," she wrote on Twitter.

She also said Egyptian military intelligence later interrogated her, blindfolded her for two hours and eventually apologized for the conduct of the Interior Ministry.

"Those guys didn't beat or assault me," Eltahawy said on Twitter, referring to the military intelligence officers.

Eltahawy, a vocal supporter of the Egyptian revolution, was detained outside the ministry in the early morning hours on Thursday and was released about 12 hours later.

Eltahawy explained that she decided to go public with her story to let the regime know that violence will not deter the Egyptians taking part in the ongoing protests against the country's military rulers.

"What I experienced is just the tip of the iceberg of the brutality Egyptians experience everyday," she said, considering herself lucky because her dual nationality might have played a role in sparing her further abuse. "This is just the type of brutality that our revolution came about to fight."

Until Thursday, protests had raged in Cairo for five straight days, as tens of thousands flooded into Tahrir Square to demand that Egypt's military rulers step down from power.

But a truce negotiated by Muslim clerics came into effect Thursday morning and halted the clashes between protesters and the security forces.

The military rulers apologized for the deaths of dozens of pro-democracy protesters who have been killed in clashes with security forces over the past six days.

Many of the people in Tahrir Square say that an apology is not what they are looking for.

"What we want to hear is when they're leaving," said Khaled Mahmoud, whose face had to be bandaged after he was hit in the face with a tear gas canister.

The military generals also defied the protesters' demands to immediately step down.

Doing so would be a "betrayal of the trust place in our hands by the people," said Maj. Gen. Mukhtar el-Mallah, a member of the ruling military council.

"We will not relinquish power because a slogan-chanting crowd said so. … Being in power is not a blessing. It is a curse. It's a very heavy responsibility."

The military rulers -- collectively known as the Supreme Council of the Armed Forces -- have held power since former Egyptian president Hosni Mubarak was ousted in February.

Egyptians are supposed to have their first chance to participate in post-Mubarak parliamentary elections on Monday. A presidential election is set to follow next year.

Many protesters suspect that the military leaders want to retain their power even after a new parliament and president are elected.

Another member of the ruling military council, Maj. Gen. Mamdouh Shaheen, said Thursday that the pending election would proceed as scheduled.

Another prominent U.S.-Egyptian filmmaker, Jehan Noujaim, was also detained near Tahrir on Wednesday. She was released Thursday after being charged with throwing firebombs and rocks at the Interior Ministry and destroying public property, her lawyer said.

The Committee to Protect Journalists called on Egyptian authorities to investigate Eltahawy's arrest and beating and condemned the detention of Noujaim.

With files from The Associated Press