Iraq starts new assault on Islamic State group in Mosul
Iraqi security forces have launched a new assault on Islamic State (IS) militants in the city of Mosul.
Troops say they made gains in a few hours as they try to drive rebels out of the last remaining strongholds in Mosul's Old City they still control.
On Friday, the government dropped leaflets urging civilians to flee.
Hundreds of thousands of civilians have fled the northern city since the offensive to reclaim it was launched in October last year.
The government announced the recapture of eastern Mosul in January but the fight for complete control of the western half continues.
Thousands of Iraqi security forces, Kurdish Peshmerga fighters, Sunni Arab tribesmen and Shia militiamen, assisted by US-led coalition warplanes and military advisers, are involved.
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Iraq's elite counter-terrorism units, the regular army and the federal police - supported by the air power of the US-led coalition - launched the new phase on Saturday.
"Army forces attacked al-Shifaa neighbourhood and the Republican Hospital, federal police forces al-Zinjili neighbourhood, and counter-terrorism forces attacked al-Saha al-Oula neighbourhood," the Joint Operations Command said.
The air strikes pose an additional risk to civilians caught in the fighting in narrow, packed streets around the Old City.
On Thursday, the US admitted that at least 105 Iraqi civilians were killed in an air strike it carried out in Mosul in March.
Iraq has also opened an inquiry into claims that its forces abused and killed civilians in the battle for the city.
To the west of Mosul, a senior Iranian Revolutionary Guard commander helping a mainly Shia militia in its battle against IS was killed, Tehran-based Tasnim news agency reported on Saturday.
Earlier this month, coalition officials estimated the number of militants in Mosul to be under 1,000 - compared with 3,500 to 6,000 militants in and around the city before the offensive began last October.
The United Nations has said the battle has left more than 8,000 civilians dead or wounded, but that figure only comprises people transferred to medical facilities.
Iraq's military does not release casualty figures, but US Gen Joseph Votel told a Congressional hearing at the end of March that at least 774 Iraqi security personnel had been killed and 4,600 wounded.
More than 580,000 civilians have also been displaced by the fighting, among them 419,000 from western Mosul, the Iraqi authorities say.