NEW YORK ( TheStreet) -- The Egyptian Army has overthrown the government of Islamist President Mohamed Morsi and set up a transitional government, according to media reports.The top army commander, General Abdel Fattah al-Sisi, addressed the nation in a radio announcement in which he declared the suspension of the months-old Islamist-tinged constitution. Sisi indicated his forces were supported by a broad coalition, and that a meeting of leadership has agreed on a roadmap for a return to democratic rule. The senior leadership of the Muslim Brotherhood was being detained from leaving the country, according to Reuters. According to Al-Jazeera, the head of the Supreme Constitutional Court, Adli al-Mansour, will be sworn in as interim head of state on Thursday. Large crowds were shown celebrating in Tahrir Square beneath celebratory fireworks in video from CNN. The Obama administration has been careful in its word choice regarding the situation in Egypt. According to CNN, State Department spokeswoman Jen Psaki said Wednesday that the United States was "very concerned about what we are seeing on the ground," adding that "the Egyptian people deserve a peaceful political solution to the current crisis." Viewed as a military coup of a popularly elected president, Wednesday's action could make it difficult for the U.S. to support the interim Egyptian government. Morsi was elected to lead the government just a year ago, following the resignation of previous longtime ruler Hosni Mubarak in February 2011. Mubarak fled Egypt and resigned after weeks of similar widespread public demonstrations. Morsi oversaw the adoption of the constitution in December of last year. Morsi released a statement published in Morsi's name on his official Facebook page after Sisi's speech, saying the measures announced amounted to "a full military coup" and were "totally rejected," according to Reuters. Western media reports indicate that pro-Morsi media operations have been shut down. A translation of Sisi's speech in video on CNN said he indicated "a code of ethics" would be established for the media to follow. Sisi also called on "Egypt and all its diverse groups" to continue a peaceful process to end the crisis. Egypt has been rocked in recent days by public demonstrations involving, by some accounts, millions of protestors, calling on Morsi to step down. Responding sympathetically to the protests, the Army earlier in the week had issued an ultimatum to Morsi and his government, calling for a shared power arrangement to be set up with opposing groups within 48 hours or face removal. U.S. markets Tuesday and Wednesday reacted to the uncertainty in Egypt, and oil prices pushed above $100 a barrel, a 14-month high. Egypt controls the Suez Canal, a key shipping route for Mideast oil. Disruption of traffic in the Suez could cripple oil supply. For more on oil prices, see Jeanne Yurman's interview with independent floor trader Cindy Wexler at the New York Mercantile Exchange and other coverage Wednesday on TheStreet. -- Written by Carlton Wilkinson in Asbury Park.