CAIRO — Egypt's benchmark stock index has rebounded after three consecutive days of losses, as the government moved to allay mounting frustration with the pace of reforms and accountability in the country. The Egyptian Exchange's EGX30 index closed 2.4 percent higher on Wednesday, recouping most of the 2.8 percent decline a day earlier. The market had fallen since Sunday as demonstrators blasted the pace of the reforms following the Jan. 25 uprising that ousted former President Hosni Mubarak. On Wednesday, the interior minister, who oversees the security forces, fired nearly 600 top police officers. The move was intended to ease frustrations over the sluggish prosecution of officers accused in the killing of some of the nearly 900 people who died during the revolution.