(CNN) -- Mali's prime minister abruptly resigned Tuesday on state television, a day after he was arrested by a group of soldiers loyal to a former coup leader.
The development is another blow to the stability of a country once hailed as a model of democracy in Africa, but one derailed by a coup and an uprising of Islamist militants.
Cheick Modibo Diarra, a former NASA engineer, who holds U.S. citizenship, was set to fly to Paris for medical care Monday, when he received notice that his bags had been removed from the plane, said a close aide, who did not want to be named.
Diarra decided to stay home, where three pick-up trucks with armed soldiers pulled up at 11:00 p.m. and took him away to military headquarters in Kati, five miles north of the capital Bamako, the official said. There he met with former coup leader Capitaine Amadou Sanogo.
Armed soldiers brought the former prime minister to broadcaster ORTM around 1 a.m., said TV technician Adama Haidara. "Mr. Diarra looked tired, worn out," he said.
The soldiers gave him a statement to read.
"I cannot say if he was forced," Haidara said. "He looked unharmed."
In his televised appearance on the military controlled broadcaster, Diarra did not offer a reason for his resignation, except for a vague statement that he solemnly delivered.
"Our country Mali is going through the most difficult period in its history," he said. "During this time of crisis, the men and women of this country -- uncertain of what is going to happen to their country -- find themselves in an unfortunate situation.
"That's why I, Cheikh Modibo Diarra, have resigned with all my government, on this day, Tuesday, 11 of December of 2012."
Diarra's whereabouts are yet unknown, but his aide believes he is still in Bamako.
"He was not injured when the military arrested him last night," he said, "but he has not come into his office today."
"The arrest was made by a small force loyal to Sanogo," said army spokesperson Colonel Idrissa Traore. "The majority of the military officers in Bamako were not informed about the arrest of Mr. Diarra, and no one knows what will happen now," he said.
Mali held its first democratic elections in 1992 after decades of military rule, and had a strong democracy for the most part.
That was until March, when a group of soldiers toppled the government, which it accused of not providing adequate equipment to battle ethnic Tuareg rebels roaming the vast desert in the north.
The president disappeared from sight.
The Tuareg rebels took advantage of the power vacuum and seized parts of the north. They have always wanted independence, and have staged several rebellions since the 1960s.
After Libyan leader Moammar Gadhafi was killed and Libya plunged into chaos, Tuaregs, who had fought by his side, took weapons to Mali to ramp up their conquest.
A power struggle erupted between the Tuaregs and local al Qaeda-linked radicals -- including Ansar Dine -- who prevailed and seized control of two-thirds of northern Mali, an area the size of France.
The international community is also worried that al Qaeda's north African wing is expanding into Mali.
U.S. officials have said that the wing, the al Qaeda in the Islamic Maghreb, is linked to the deadly Benghazi attack that killed the U.S. ambassador to Libya and three others.
Tuareg rebels have retreated from the well-armed militants, but have vowed to fight back and establish their own country in the north, which they call Azawad.
And as the world seeks a solution, the Islamist militants are busy applying their strict interpretation of sharia law, including the banning of music, smoking, drinking and watching sports on television.
They also publicly stoned a couple to death in July for reportedly having an affair.
Public executions, amputations, floggings and other inhuman punishments are becoming common, the United Nations says.
At least four times this year, the militants have destroyed Timbuktu's historic tombs and shrines, claiming the relics are idolatrous. The picturesque city was once an important destination for Islamic scholars for its ancient and prominent burial sites and is a UNESCO World Heritage Site.
West African states and international leaders say a rapid military intervention is essential to solving the security crisis.
When soldiers seized the capital, the regional and international powers put pressure on them to restore democratic rule.
Sanogo conceded and transferred power to interim President Dioncounda Traore, who was appointed by the Economic Community of West African States (ECOWAS). Traore appointed Diarra interim prime minister.
Traore fled to a Paris hotel after being beaten unconscious in a May 21 attack that occurred in the presidential palace.
Prime Minister Diarra took over the country's leadership until Traore returned.
CNN's Faith Karimi contributed to this report