India said Thursday it knows the location of its 40 workers abducted in violence-torn Iraq, as several of their families said they spoke with the captured men who were scared but "safe".

Armed militants abducted the workers on Monday from a stadium where they were working in the northern city of Mosul but no demands for ransom have been made, the Iraqi Red Crescent Society told AFP.

The Indian citizens were being held together with other abducted foreigners and "every avenue will be pursued" to secure their release, Indian foreign ministry spokesman Syed Akbaruddin said.

"We have been informed by the Iraqi foreign ministry that they have tracked down the location where the Indian nationals are held," Akbaruddin said at a briefing in New Delhi.

The ministry on Wednesday revealed the workers had been abducted from Mosul, which Sunni militants have overrun as part of a deadly and spreading insurgency. But it said it did not know who had taken the workers or where they were being held.

Forty-nine Turks including diplomats and children were also kidnapped from the Turkish consulate in Mosul last week in the crisis.

The discovery of the whereabouts of the Indian workers, which were not revealed, comes as families said they had spoken with the men.

Charanjit Singh said his brother called him on Wednesday "for a couple of minutes" to tell him that their captors claimed they would be released if someone from the government made contact.

"He said he and his co-workers from India were all safe and not held hostage," Singh told The Hindu from his home in northern Punjab state.

"They say (the militants) will release them if someone responsible from the Indian military or government comes to collect them," Singh added.

Parminder Singh said he had spoken with his brother Kamaljit who said the "rebels are feeding us and treating us well".

Parminder told AFP from a village in Punjab that his brother was a 30-year-old refrigeration mechanic whose wife and two children were anxiously awaiting his safe return.

Parminder, who last spoke with his brother on Wednesday, said the 40 were part of a larger group of Indians. But the militants released some workers whom they discovered were Muslim.

- Situation tenuous -

Some of the relatives met Foreign Minister Sushma Swaraj in Delhi on Thursday and were briefed on efforts to secure the group's release.

"The minister told us that they were reasonably sure about the safety of the entire group. I just hope for the best," Gurpinder Kaur, whose brother was abducted, told AFP.

The government has dispatched a former ambassador to Baghdad to coordinate rescue efforts while the chief minister of Punjab province -- where most of the workers hail from -- has said he is willing to pay a ransom to gain their freedom.

Akbaruddin said the government was working with its Iraqi counterparts and local aid groups but the security situation remained tenuous.

"In situations where there exists no single authority, where there exists no established interlocutors, we are trying to do our best in the circumstances."

The Iraqi Red Crescent Society said it has learnt that armed militants loaded the 40 men into vehicles at the stadium where they were working.

"We don't know what happened to them," society president Yaseen Ahmed Abbas said by phone from Baghdad.

"It is difficult to talk to the insurgents, there is no official who we can talk to."

The group had been working for the Tariq Noor Al Huda company, and were among some 100 Indian nationals including almost 50 nurses caught in Iraq's conflict areas.

Militants from the Islamic State of Iraq and the Levant (ISIL) have taken over vast swathes of territory as they advance on Baghdad, amid fears that the country could fall apart.

anb-pr-str-bb/tha/jom