Mali's government says it has launched an investigation into the shooting deaths of 16 Islamic preachers at a military checkpoint in the country's central region.

In a statement Sunday, the government said eight Malians and eight Mauritanians had been killed by gunshot in an overnight Saturday incident at the Diabaly checkpoint in the Segou region. The government expressed regret over the deaths and condolences to the victims' families.

Earlier reports said that 12 Mauritanians we killed. Security officials were quoted as saying that the soldiers opened fire after the group failed to obey a command to stop.

The group was in a vehicle on the way to a conference in Mali's capital Bamako when it was stopped at the checkpoint more than 400 kilometers further north.

Reports say the preachers were from the moderate Dawa sect and were not armed, but could have been mistaken for terrorists because of their long beards.

Malian troops are on high alert after Islamic militants took control of the country's north, following a military coup in Bamako in March.

The current leader of the al-Qaida-allied militant group Ansar Dine, which controls northern Mali , is a former Dawa sect member.

The Malian government is trying to regain control of the north from Ansar Dine and other Islamist militant groups.

According to an Algerian official and a spokesman for Ansar Dine, a senior commander of al-Qaida in the Islamic Maghreb died in a car accident Sunday in the city of Gao in northern Mali. The Algerian national Nabil Makhloufi, known as Nabil Alqama, was a military commander of AQIM in the Sahara desert. He was believed to be the deputy of Abu Zeid, the AQIM leader responsible for the death of at least two foreigners kidnapped by his group.