Mohamed ElBaradei, the Nobel laureate who has become a leading opponent of President Hosni Mubarak of Egypt, returned to Cairo on Thursday in an attempt to galvanize youth-led street protests that extended into a third day across the country. Smoke rose over the city of Suez on Thursday as sometimes violent protests continued there. In the capital, a relative calm settled over the streets in anticipation of a new wave of demonstrations anticipated for Friday.
Raising the stakes, the Muslim Brotherhood, long the country’s largest organized opposition group, intends to end days of official inaction to enter fully into protests on Friday. On its Web site, the group said it would join “with all the national Egyptian forces, the Egyptian people, so that this coming Friday will be the general day of rage for the Egyptian nation.”
Mr. ElBaradei, the former head of the International Atomic Energy Agency who has sought to refashion himself as pro-democracy campaigner in his homeland, is viewed by some supporters as capable of uniting the country’s fractious opposition and offering an alternative to Mr. Mubarak’s authoritarian rule. Critics view him as an opportunist who has spent too little time in the country to take control of a movement which began without his leadership.
But his return adds a new element to the unrest in several big cities that has shaken assumptions that Mr. Mubarak’s security apparatus can keep a tight lid on popular protest.
Safwat el-Sherif, the secretary general of the ruling National Democratic Party, called for restraint from both security forces and protesters, and he raised the possibility of opening a dialogue with the young people who have powered the demonstrations. At the stock exchange, meanwhile, the benchmark Egyptian index fell to its lowest level in over two years, shedding more than 10 percentage points and forcing a brief suspension of trading, news reports said.
“It’s clear today that the inability to control the situation in the streets yesterday is panicking investors,” The Associated Press quoted Ahmed Hanafi, a broker with Guthour Trading, as saying. “The drop we saw yesterday is being repeated. At this rate, it’s going to continue to fall hard.”
Despite the ban issued Wednesday on public gatherings, organizers continued to use social networking sites like Facebook and Twitter to prepare for Friday.
Since they erupted Tuesday, the protests have largely seemed spontaneous and leaderless, propelled by young demonstrators with no affiliation to Egypt’s small and largely toothless opposition groups.
Now the older opponents are rushing to catch up. “It was the young people who took the initiative and set the date and decided to go,” Mr. ElBaradei said Wednesday with some surprise during a telephone interview from his office in Vienna on Wednesday.
On Thursday, Dr. ElBaradei insisted that he would attend the Friday demonstrations and urged Mr. Mubarak to step down. “He has served the country for 30 years and it is about time for him to retire,” he told Reuters. “Tomorrow is going to be, I think, a major demonstration all over Egypt and I will be there with them.”
The streets of downtown Cairo were largely quiet on Thursday except for a small knot of protesters outside the Egyptian lawyer’s syndicate. Uniformed police stood guard nonetheless in Tahrir Square, an epicenter of the demonstrations.
Egypt has an extensive and widely feared security apparatus, and it deployed its might in an effort to crush the protests. But it was not clear whether the security forces were succeeding in intimidating protesters or rather inciting them to further defiance.
The government said about 800 people had been arrested throughout the country since Tuesday morning, but human rights groups said there had been more than 2,000 arrests.
Abroad, there were growing expressions of concern from Egypt’s allies. The United States ambassador in Cairo, Margaret Scobey, called on the government “to allow peaceful public demonstrations,” and Secretary of State Hillary Rodham Clinton reiterated that call in blunt remarks to reporters. The German foreign minister, Guido Westerwelle, speaking to reporters, said, “We are very worried about how the situation in Egypt is developing.”
But Egyptian officials, at least publicly, were mostly dismissive.
In a statement, Mr. Mubarak’s National Democratic Party reiterated the government’s assertion that the protests were engineered by the Muslim Brotherhood. Abdel Moneim Said, a member of the N.D.P. and the chairman of Al Ahram, which publishes the state-owned newspaper of the same name, explained the government’s lack of concern.
“The state is strong,” he said. “There is a history of there being a moment of exhaustion, and there is a kind of resilience on the part of the government. It happened with the terrorist groups.”