CAIRO — Besieged by two weeks of protests, Egyptian president Hosni Mubarak's regime has offered once-unthinkable political concessions and started negotiations with its fiercest adversaries.

Some things in Egypt, however, don't change so quickly.

The Egyptian military has rounded up scores of human rights activists, protest organizers and journalists in recent days without formal charges, according to watchdog groups and accounts by the detainees. While most arrests have been brief — lasting fewer than 24 hours — experts say they're a sign that the regime's notorious tradition of extrajudicial detentions is continuing even as Mubarak appears to be on his way out of power.

Arbitrary arrests by police forces are among Egyptians' bitterest and longest running complaints against their government, which gives security services sweeping powers under a state of emergency that's been in place almost nonstop since 1967.

The perpetrators of the latest arrests, however, are Egyptian army soldiers, deployed on the streets for the first time in more than two decades after the police all but disappeared following clashes with protesters on Jan. 25. The man most likely to lead the transition to a post-Mubarak era, Vice President Omar Suleiman, is Mubarak's longtime intelligence chief.

"If the military is going to continue to arrest activists and arrest journalists, that does point to a pattern of a crackdown," said Heba Morayef, Middle East researcher for Human Rights Watch. "It's a worrying sign of things to come ... because the military is going to play a big role going forward."

At least 75 Egyptian activists and demonstrators and approximately 30 foreign journalists have been captured since the protests began, she said, including at least seven people who disappeared last Thursday as they were returning from a meeting with opposition leader Mohammed ElBaradei. That was the day that targeting of activists and journalists appeared to escalate following heavy fighting between protesters and pro-Mubarak forces in Tahrir Square.

All the foreign journalists and roughly half of the Egyptians have been released. Most were held for less than 24 hours, Morayef said.

On Sunday, the military briefly detained a correspondent for the Al Jazeera news channel's English-language service near Cairo's Tahrir Square, epicenter of the demonstrations in the capital. The reporter, Ayman Mohyeldin, an American citizen who was released Sunday evening, has been the most visible face of a network whose around-the-clock, often passionate coverage of the uprising has incensed Egyptian authorities.

Mostafa al Hassan, an Egyptian lawyer who was detained and questioned for two days last week, said that the message from the military was: "We know what you're doing and we can stop you at any time."

Hassan was among 35 people arrested in a raid Thursday evening at the Hisham Mubarak Law Center, which has provided legal aid and other assistance to demonstrators.

Security forces — including the hated baltagia, or state-sponsored thugs in plainclothes — stormed into the building a few blocks from Tahrir Square and ransacked the offices, seizing laptops, hard drives and two safes. They then tied the captives' hands and hauled them away in a bus to a military camp in a suburb outside Cairo.

Among the group was a U.S. citizen, Dan Williams, a Human Rights Watch researcher, as well as a foreign researcher for Amnesty International and two European journalists. The foreigners were released on Friday but the Egyptians were held for a second day.

The group was blindfolded and seated in a hallway, which suggested to Hassan that the jail cells were full of other detainees. In his first interrogation that night, a military officer told him that he wasn't in trouble and that his arrest was "to protect you from thugs."

That night, however, the prisoners heard the voices of three people who sounded like they were being abused. Oddly, one of the voices appeared to be a recording, according to the center's former director, Ahmed Seif al Islam, who suggested that it was a form of psychological torture by the military.

In its most recent human rights report on Egypt last March, the State Department said that security forces and prison guards "often tortured and abused prisoners and detainees, sometimes in cases of detentions under the Emergency Law, which authorizes incommunicado detention indefinitely, subject to a judge's ruling."

"We don't really know how the military deals with internal policing," said Morayef of Human Rights Watch. "The targeting of activists is very reminiscent of the state security approach."

Their captivity yielded some insights into the military's position on the political crisis, Islam said. The officer who interrogated him acknowledged that Mubarak was "finished," but that the uprising "must stop because the army will not accept this kind of end for one of its leaders."

The first night, the detainees were given only bread and jam to eat, and they slept on the floor without blankets. The next night their captors gave them one blanket to share among three people.

Saturday morning, they were allowed to leave. Islam, among the last to be released, retrieved his cell phone and laptop and hailed a taxi back into Cairo. After a brief stop at home to change clothes, he returned to Tahrir Square to rejoin the demonstrators.

"To send a message," he explained, "that we will not stop."

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