The 39 Indian workers held hostage by Islamic State jihadists in Mosul in Iraq since the past two months "remain in custody", the government said Wednesday, adding that in "war situations, there is no certainty about safety, especially in custody".

External affairs ministry spokesperson Syed Akbaruddin, said at a press briefing that the Indians who were working for a Turkish construction company in Mosul when they were abducted in mid-June, continued to remain in custody, according to the "last information" that the Indian government received about the men four-five days ago.

"In war situations, there is no certainty about safety; in conflict situations there is no certainty about safety, especially in custody," he said. The situation in Mosul was dynamic and they were keeping in touch with the Indian nationals who are in custody, he said.

"Our last information, which is not outdated, was that the Indian nationals remain in custody," he said of the Indian workers, who mostly hail from Punjab.

He also said that following the IS militants expanding their hold, including into Kurdish areas, India was monitoring the situation and what its impact will be on India's national interests and on Indian nationals.

Mosul was overrun by militants of the Islamic State of Iraq and the Levant, who now call themselves the Islamic State, in June. The militants have over-run large swathes of area in northern Iraq and are currently on the verge of taking over Mosul Dam, thus controlling the source of water and electricity.

Earlier, 46 Indian nurses who were stranded in Tikrit were set free by the militants after hectic negotiations. India has flown home hundreds of Indians from Iraq following the surge by the militants.