* Whereabouts unknown and no ransom demand received
* Some 46 nurses stranded in rebel-controlled Tikrit (Adds details of other kidnappings, quotes)
By Frank Jack Daniel
NEW DELHI, June 18 (Reuters) - Forty Indian construction workers have been kidnapped in Iraq's second largest city of Mosul, which fell to Sunni insurgents last week, India's foreign ministry said on Wednesday.
The identity of the kidnappers and the whereabouts of the workers are unknown, foreign ministry spokesman Syed Akbaruddin told a news briefing. No ransom demand has been received.
Islamist militants have long considered India a target. A recent al Qaeda video called on Indian Muslims to follow the example of Syria and Iraq and launch a jihad, or holy war, against the New Delhi government.
On Monday, India's new government issued a strong condemnation of the insurgency and said it stood firmly by Baghdad, breaking from India's traditionally nuanced diplomacy. It was not immediately clear why Indian workers were targeted.
"The Red Crescent confirmed to us that as per their information, 40 Indian construction workers have been kidnapped," Akbaruddin said. "We won't leave any stone unturned to help every single Indian national."
Militants from the Islamic State in Iraq and the Levant (ISIL), along with other Sunni rebels, are reported to have abducted dozens of foreigners as they swept through towns in the Tigris valley north of Baghdad in recent days.
Sixty people including workers from Turkey, Pakistan, Bangladesh, Nepal and Turkmenistan have been taken from a hospital construction site near the oil-rich city of Kirkuk, Turkey's Dogan news agency said.
Insurgents seized eighty Turkish nationals including diplomats, soldiers and children workers in Mosul last week.
Most of the Indian hostages are from the north Indian state of Punjab and were working for a Baghdad-based company called Tariq Noor Al Huda, Akbaruddin said.
A former employee told Reuters the company had told him the Indians were now safe and being moved towards Kurdish controlled areas of Iraq. Reuters was not able to independently confirm this or contact the company directly.
The sister of one of the men abducted said he had been out of contact since last Sunday.
"His phone has been switched off. We are tense and are wondering what happened to him," Gurpender Kaur told TV news channel CNN-IBN. "Until then, at least we were able to speak for a second or two, but now even that is not possible."
About 10,000 Indian nationals work in Iraq, mostly in areas unaffected by the fighting between the Islamic State of Iraq and the Levant (ISIL) and the national army. About 100 Indian workers are trapped in areas overrun by ISIL, Akbaruddin said.
The Indian government has contact with many of them, including 46 nurses, and has sent a senior envoy to Baghdad to support repatriation efforts.
The nurses are stranded in Tikrit, which is under militant control, with many of them holed up in the hospital where they work. Nurses who spoke to the Indian media said they had been treating people wounded in fierce street fighting.
The Red Crescent, a humanitarian group, has contacted the nurses and is providing assistance, Akbaruddin said.
ISIL fighters, who aim to establish a Muslim caliphate across the Iraqi-Syrian frontier, launched their revolt by seizing Mosul and have since swept through the Tigris valley towards Baghdad. (Additional reporting by Sruthi Gottipati, Shyamantha Asokan Malini Menon and Manoj Kumar; Editing by Douglas Busvine and Tom Heneghan)