The Syrian opposition’s defense minister has resigned after reports of disagreements with the group’s head, opposition sources said on Monday.

Dissident Asaad Mustafa’s resignation from the government-in-exile highlights divisions among President Bashar al-Assad's opponents.

Mustafa, in his sixties,had been appointed to his post in November as part of a plan by the opposition National Coalition to administer rebel-held areas of the war-torn country, according to Reuters news agency.

A rebel source close to Mustafa told Reuters he resigned on Sunday night to protest a lack of funds for his fighters from Coalition head Ahmed Jarba.

But a source in the Coalition said Mustafa left after Jarba refused to appoint him as provisional prime minister, a post currently held by Ahmed Tumeh, a moderate Islamist.

Jarba will remain head of the Coalition until June, when a new leader will be elected unless his term is extended.

Al Arabiya with Reuters