Forty-six Indian nurses trapped in Iraq's conflict were freed on Friday after getting caught up in a swift militant offensive that has overrun swathes of territory and threatens "Syria-like chaos".

Their captivity, along with the capture of 39 other Indian workers in Mosul, left Indian authorities scrambling to secure their release in the first foreign crisis for the new rightwing government of Prime Minister Narendra Modi.

Among dozens of foreign nationals caught up in a swift jihadist-led offensive that saw swathes of territory fall from government control, the nurses were originally working at a hospital in executed Iraqi dictator Saddam Hussein's home town of Tikrit when insurgents took it on June 11.

They were later moved further north to Mosul, Iraq's second biggest city and the first to fall in the onslaught, before finally being released on Friday and taken to the nearby Kurdish regional capital Arbil.

The nurses were then due to board a specially chartered plane bound for their home state of Kerala in southern India.

It was not immediately clear if the nurses were actively seized by militants leading the offensive when Tikrit fell, or if they were simply stranded.

Indian foreign ministry spokesman Syed Akbaruddin hailed their release, telling reporters in New Delhi that "hope... has triumphed".

"Diplomacy works through the front door," he said. "We are using other doors. How the doors were used and knocked on, how they were opened up, is a story for another day."

Akbaruddin declined to say whether a ransom had been paid or to comment on how their release was secured.

- Home on Saturday -

Kerala Chief Minister Oommen Chandy said he hoped they would be back in India on Saturday morning.

The news was hailed by the women's relatives.

Sayona Thomas, a nurse from Palakad in southern Kerala, called her father to tell him that their captors had agreed to release them.

"My daughter told me that today the militants have agreed to release them and are taking them to Arbil airport. We are so happy and I thank God for everything," he told the Indian channel Manorama News.

An Indian diplomat, speaking on condition of anonymity, told AFP that the group of nurses was separate from the other 39 Indian workers held in Mosul.

India estimates that around 120 of its nationals have been caught up in the unrest in Iraq, where some 10,000 Indian expatriates are working.

The country's foreign ministry last month announced it would stop granting Indians permission to travel to Iraq for work, and advised those travelling for other purposes to cancel their plans.

The father of one of the nurses, Chakiriyamthadathil Joseph from southern Kerala state, reported that five of the women had sustained minor injuries while being moved from Tikrit to Mosul because of an explosion.

"She told us not to worry and asked us to pray," Joseph told AFP, saying he had spoken late on Thursday to his daughter on her mobile phone which she had hidden from her captors.

A spokesman for the Indian foreign ministry, confirming the nurses changed location on Thursday, denied there had been a bomb blast but said some of them had sustained minor injuries from broken glass.

Dozens of Turks have also been seized in Iraq.

More than 30 Turkish truck drivers were freed on Thursday after three weeks in captivity, but a separate group of almost 50 Turks seized in an attack on the Turkish consulate in Mosul last month remain in captivity.

Militants led by the Islamic State (IS) jihadist group launched a lightning offensive on June 9, and swiftly seized large chunks of five provinces in an onslaught that has displaced hundreds of thousands and alarmed the international community.

The conflict has had a heavy cost on Iraqi forces, with nearly 900 security personnel killed in June.

UN special envoy Nickolay Mladenov has warned that Iraq risks descending into "Syria-like chaos", referring to the more than three-year conflict in Iraq's neighbour to the west.

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