LAGOS, March 9 (Xinhua) - Nigerian Acting President Goodluck Jonathan on Monday appointed Aliyu Gusau as a new security adviser.

Retired Lt.-Gen.Gusau took the position from Sarki Mukhtar. The new national security adviser held the same position for former President Olusegun Obasanjo.

Ima Niboro, spokesman for the acting president, said in a statement that Jonathan thanked Mukhtar for his services to the nation and wished him well in his future endeavors.

No reason for the move was given in the statement.

The decision was made after a marathon meeting of the National Security Council (NSC) presided over by the acting president, the statement added.

The crisis in Jos, central Nigeria, took the center stage at the meeting, according to the statement. The meeting was attended by top government officials and security chiefs, including the sacked national security adviser.

On Sunday morning, Islamist pastoralists wielding machetes attacked the town of Jos, a Christian village in Nigeria's Plateau State. At least 500 people were killed, mostly women and children, according to the state police spokesman.

The development came after more than 300 people died during the crisis that erupted on January 17 in Jos in Plateau State, when some youths attacked worshippers at St. Michael's Anglican Church in Nasawara Gwom.

The National Assembly by a unanimous resolution on Feb. 9 empowered Jonathan as acting president after a prolonged power vacuum created by President Umaru Yar'Adua's emergency medical trip to Saudi Arabia in November.

The president was brought back to the country in the early hours of Feb. 24.