By DAVID D. KIRKPATRICK, BEN HUBBARD and ALAN COWELL

CAIRO — Egypt’s military moved forcefully to seize power from President Mohamed Morsi on Wednesday, deploying tanks and troops in Cairo and other cities, restricting his travel and convening an emergency meeting of top civilian and religious leaders to devise an interim government and lay the groundwork for new elections.
 Ahramonline, the government’s official English-language Web site, said the military had informed Mr. Morsi that he was no longer head of state. There was no word on Mr. Morsi’s whereabouts.

The military’s actions came as enormous crowds of the president’s supporters and opponents filled the streets of the capital and soldiers were deployed in significant numbers to keep the spiraling political crisis from going out of complete control.

State radio said that the emergency meeting, which included Mohamed ElBaradei, a prominent Egyptian statesman who has emerged as a leading critic of Mr. Morsi, along with top Muslim and Christian leaders, had adjourned after several hours and a “road map” for a post-Morsi government would be announced later.

The developments followed the lapse of a 48-hour deadline imposed by the military generals on the increasingly isolated president to meet the demands of millions of Egyptians disaffected with the one-year-old governance of Mr. Morsi, the first democratically elected leader of Egypt.

By 6:30 p.m. military forces began moving around Cairo. Tanks and troops headed for the presidential palace — although it was unclear whether Mr. Morsi was inside — while other soldiers ringed the nearby square where tens of thousands of the president’s supporters were rallying.

Many of the Islamists had armed themselves with makeshift clubs, shields made of potcovers or metal scraps and plastic hard hats, and there were small scuffles with the better-armed soldiers. Some soldiers fired their weapons in the air. But the military forces held back.

Soldiers also were seen erecting barbed-wire fences and barriers around a barracks were President Morsi may have been working, Reuters reported, quoting witnesses.

Mr. Morsi’s senior foreign policy adviser, Essam el-Haddad, issued an open letter Wednesday afternoon on his official Web page lamenting what he called the imminent takeover of Egypt’s first freely elected government.

“As I write these lines I am fully aware that these may be the last lines I get to post on this page,” he wrote. “For the sake of Egypt and for historical accuracy, let’s call what is happening by its real name: Military coup.”

Security officials said the military’s intelligence service had banned any travel by President Morsi and senior Islamist aides, including the Muslim Brotherhood’s supreme guide, Mohamed Badie, and his influential deputy, Khairat el-Shater.

People close to the president said at around the same time that talks with the generals continued but looked increasingly futile. A decisive move was expected within hours, these people said, although the president and his advisers remained at liberty.

With millions of Egyptians waiting to see what the military would do, Mr. Morsi reiterated in a Facebook posting what he had said in a long and rambling televised speech Tuesday night, vowing to stay in power as Egypt’s first democratically elected president following the 2011 revolution that overthrew Hosni Mubarak.

“The presidency reaffirms that violating constitutional legitimacy threatens democratic practice by veering off the right track and threatens the freedom of expression that Egypt has lived since the revolution,” the statement said.

Among those called to the meeting with the generals was Mohamed ElBaradei, the former United Nations diplomat who has been tapped by the protesters demanding Mr. Morsi’s ouster as one of their negotiators over a new interim government, Reuters reported, citing unnamed official sources.