Faure Gnassingbe took his father's place as the president of Togo, swearing an oath before the country's top judges to fulfill the duties of president, and uphold his country's constitution.
Ruling party officials and the army's leadership attended the inauguration, as well as several African diplomats. Western diplomats were not present.
The ceremony took place at the presidential palace in the capital Lome, despite protests from the West African regional body known ECOWAS. The secretary-general of the 15-nation grouping, Mohamed Ibn Chambas, failed to prevent the induction ceremony from taking place.
The regional body, which includes Togo, will hold an extraordinary summit Wednesday in Niger to discuss the situation.
Mr. Gnassingbe, formerly a lawmaker and government minister, was named president by the military after his father Gnassingbe Eyadema died suddenly Saturday. Parliament made a constitutional change Sunday that allows the 39-year-old Mr. Gnassingbe to stay in power until 2008. The former constitution called for elections within 60 days in case of the president's death.
The international community has condemned the transfer of power, saying it amounts to a military coup. The French foreign ministry called for swift elections in its former colony.
Nigerian President Olusegun Obasanjo, the current head of the African Union, said African leaders should not accept the new leadership in Togo until there is a democratic transition.
Republic of Congo President Denis Sassou-Nguesso says African leaders should promote democracy, but also ensure peace and security. He said Togolese need help to manage what he called a very "delicate" situation.
Mr. Eyadema had been in power 38 years, and last won elections in 2003 said to be marred by fraud and intimidation.
Togo's three main opposition parties are demanding a dialogue with the new authorities in Lome. An opposition party leader, Leopold Gnininvi, said there have been no major protests, but there were reports that security forces prevented some university students from leaving their campus to take to the streets.
Mr. Gnininvi told VOA that in his opinion the president is illegal if elections are not held.
He said if the opposition's appeals for dialogue are rejected they will be forced to organize protests.