Fernando Linares, a deputy in the Congress that Mr Serrano dissolved, said the Defence Minister 'has taken control this morning after strong talks with Serrano. Garcia Samayoa is in power'. Mr Linares, a member of the opposition National Centre Union, said the military wanted to stay out of politics 'but it cannot because the crisis is very grave'.
The country's official human rights investigator, Ramiro de Leon Carpio, also confirmed that Mr Serrano had been ousted.
There were reports that Gen Garcia Samayoa would convene the dismissed Congress as early as today to pick an interim president.
Earlier, members of Guatemala's abolished Congress and the Constitutional Court were summoned to the National Palace amid rumours of Serrano's resignation. Hundreds of people outside the palace shouted pro-democracy slogans as the deputies began to arrive. 'Serrano has fallen, Serrano has fallen,' they cheered.
Amid the chaos, Mr Serrano and his chief of staff, Colonel Francisco Ortega Menaldo, left the palace and sped away in a car to an unknown destination.
On Monday night, after rumours of his resignation swept the capital, Mr Serrano went on television and radio to deny them. Mr Serrano, a declared supporter of democracy, said he took emergency action on 25 May because the country was sliding into 'anarchy' after two weeks of violent protests over declining living standards.
Mr Serrano, 48, was elected president for a five-year term in 1990 and took office in January 1991. Until Tuesday, he appeared to retain the support of the Guatemalan military, a powerful institution in a country with a long history of military dictatorships. But other sectors began to desert him soon after he took absolute power.
The United States, the European Community and Japan announced suspension of tens of millions of dollars in aid, and the Organisation of American States was to meet tomorrow to consider sanctions.