Tanzania’s former President Benjamin Mkapa, who served from 1995 to 2005, died in the early hours of Friday, President John Magufuli said in a statement.

Mkapa, the East African nation’s third president who led several regional peace mediation efforts in office and afterwards, died while receiving treatment at a hospital in Dar es Salaam, Magufuli said, without giving more details.

He declared a seven day mourning period, during which all flags will be flown at half-mast.

“Magufuli asks all Tanzanians to remain calm, patient and united during this difficult time,” a statement from his office said.

Mkapa, 81, also served as an ambassador, minister and key official of the ruling CCM party, Magufuli.Reuters