Niger's government dissolved Thursday after a no confidence vote led by an opposition group in the country's parliament.
Out of 113 delegates in the legislature, 62 voted to dissolve the government of Prime Minister Hama Amadou, who has been at Niger's helm for seven years.
Both sides said the vote was precipitated by an embezzlement scandal, following allegations that Amadou stole an estimated $1.2 million in international education aid intended for Niger's impoverished schools.
Tandja is expected to name a new prime minister within the next few days.
Soon after the vote, the ousted prime minister appeared to accept defeat, saying: "Niger's democracy has made itself heard... After four no confidence votes, today my government has fallen," Amadou said.
Niger has a population of about 12 million people and lies on the southern edge of the Sahara Desert. The arid nation has seen a succession of coups and elections since independence from France in 1960 and is regularly rated among the world's five poorest countries.