South Sudan's rebel leader has fled the country, a spokesman for his party said Thursday.

Former First Vice President Riek Machar has gone to a safe country in the neighboring East African region, Mabior Garang, a spokesperson for the SPLM-IO party, said in a posting on Facebook.

Machar is expected to hold a press conference later Friday, Garang said.

After clashes with President Salva Kiir's army in the capital of Juba on July 8th, Machar and rebel forces left the city, putting the country's peace deal in limbo. Hundreds of civilians died in the July fighting.

Government and rebel forces have recently clashed in the southern region of Yei, according to rebel leaders and local government officials.

Last week, the U.N. voted to send 4,000 regional peacekeepers to Juba. The government has not yet accepted the force and Machar said he will not return to the capital until it is deployed.

In July, Machar was removed as South Sudan's first vice president after a disputed change of leadership in his party.

South Sudan's civil war began in December 2013, and a peace deal was signed in August, 2015.

The United Nations secretary-general is launching an independent investigation into allegations that U.N. peacekeepers did not respond to prevent multiple cases of abuse and sexual violence against civilians and foreigners in South Sudan's capital.

Ban Ki-moon's spokesman said late Tuesday that the U.N. chief is alarmed by reports of the July 11 attack on a compound popular with foreigners in Juba. The Associated Press this week reported that South Sudanese troops went on a nearly four-hour rampage through the compound in one of the worst targeted attacks on aid workers in the country's three-year civil war.