Where's Baghdadi? IS leader flees Mosul as battle rages

The Islamic State group's notorious leader has reportedly fled Mosul where Iraqi forces are waging a large-scale offensive against the militants.

The comes despite Abu Bakr al-Baghdadi's commands to his followers that they must stay in Mosul and die on the battlefield.

Rumours of Baghdadi's flight seemed to given credence when the UK's foreign minister Boris Johnson confirmed that his whereabouts remain unclear, but most likely he is out of Mosul.

"Abu Bakr al-Baghdadi has ESCAPED Mosul after the terror boss told his followers: 'Do not retreat'", a tweet sent by the British Embassy in Baghdad revealed

On Thursday, Baghdadi called on his fighters to resist as Iraqi forces were poised to enter the city of Mosul where he declared a "caliphate" two years ago.

"Do not retreat," said a voice said to be Baghdadi in an audio statement released by the IS-affiliated al-Furqan media.

"Holding your ground with honour is a thousand times easier than retreating in shame," he said in the message, his first in more than a year. 

"To all the people of Nineveh, especially the fighters, beware of any weakness in facing your enemy," Baghdadi said, referring to the northern Iraqi province of which Mosul is the capital.

Some sources said that Baghdadi made the statement on the Iraqi-Syrian border and that he fled besieged Mosul.

Iraq's second city was captured by the IS group in June 2014 along with huge swathes of the north and west of the country.

A coalition offensive on Mosul began on 17 October and is expected to be a long and difficult battle to unseat the extremist group from their Iraqi stronghold.

According to the US military, IS has 3,000 to 5,000 fighters inside Mosul and another 1,500 to 2,500 in the city's outer defensive belt.

The total number includes around 1,000 foreign fighters, but militants have already dug themselves in, demolishing buildings to hinder the government's advance and placing snipers among the rubble to pick off soldiers.