Sudan army advances in central Khartoum after retaking palace / Sudan's army reclaims the capital Khartoum as RSF militia 'loses steam' / Sudan's army recaptures presidential palace in Khartoum / Sudan's army chief lands at Khartoum airport after military recaptures it from RSF / 'Khartoum is free', Sudan's army chief says after military retakes airport / Sudan's army takes full control of Khartoum, RSF remains defiant / Sudan army says it has taken full control of Khartoum / Sudan's army says it has recaptured Khartoum's airport as it seeks to liberate the capital / Sudanese army surrounds Khartoum airport in battle for capital, military sources say