Palestinian security chief quits
Dahlan resigns on medical grounds weeks after Fatah was forced out of Gaza.
He was not in Gaza when fighting broke out between the two factions. More than 100 people were killed in the conflict, while Dahlan was sidelined due to surgery on both knees.
In an interview with the Reuters news agency earlier in the month, Dahlan acknowledged mistakes and said individuals, including himself, should take responsibility for their errors.
Last month, Abbas dismissed Rashid Abu Shbak, another senior security official.