Soldiers arrested the head of one of Mali's biggest political parties and officials from the country's ousted government on Tuesday, deepening questions about whether the military is still in control even as a new civilian prime minister was appointed to the interim government.

Cheick Modibo Diarra, a former NASA scientist who served as Microsoft Corp.'s chairman for Africa until last year, is now tasked with organizing new elections in Mali after last month's coup.

His nomination as prime minister comes just days after a new interim president was sworn in after the regional group ECOWAS pressured the junta leader Capt. Amadou Sanogo into signing an accord that was supposed to pave the way to full civilian rule.

However, Sanogo has made clear in numerous statements since the agreement that he intends to continue to play an important role in Malian politics, especially after the 40-day period the interim president has in office under the terms of the constitution.

On Tuesday, soldiers detained a number of senior politicians and military officials, including many prominent in the government that was toppled last month by the junta. The European Union delegation in Mali issued a statement expressing concern about the arrests and calling for "an urgent clarification and their immediate release."

"As soon as I heard I contacted Capt. Sanogo to tell him that's not the sort of thing that should happen in a country where there is the rule of law and that he should take measures so that those who have been detained know first of all why they have been detained and that they should possibly be released," Interim President Dioncounda Traore told The Associated Press.

"He promised me to look into the matter today. So I think this is a problem that will be dealt with today except of course for those who they have things against," he said.

Among the detainees are one of overthrown President Amadou Toumani Toure's former prime ministers, the general in charge of Toure's personal military protection and the country's former defense minister.

The president of one of Mali's biggest political parties was also arrested. Soumaila Cisse was one the front-runners for the presidential election set for April 29 that was derailed by the coup.

Cisse was arrested Tuesday in front of his home in Bamako, according to Abdoul Malick Diallo, a member of parliament from Cisse's party. Diallo said that Cisse was hurt during the arrest but that he couldn't say how serious the injury was.

Late Monday, former Malian prime minister Modibo Sidibe was re-arrested by military personnel at his home, according to his aide Cheickna Diarra, who said he did not know why Sidibe was arrested or where he was being held.

Sidibe was among around a dozen politicians who were arrested immediately after the military coup. He was later released, but the majority were detained until after last week's handover to the civilian interim president.

Amid the post-coup political upheaval, separatist rebels in northern Mali declared an independent state that is larger than France. The power vacuum also has allowed an Islamic faction that wants to impose Shariah law in the area to flourish.