Isis IRaq
Fighters of the Islamic State of Iraq and the Levant (ISIL) stand guard at a checkpoint in the northern Iraq city of Mosul. Reuters

The Indian government has said all efforts are being made to free 40 construction workers captured by suspected Isis militia in Iraq's oil-rich Mosul.

New Delhi said it has not received any ransom demand from the abductors and that the whereabouts of the workers were not known. The government could also not confirm if the militants from the Islamic State in Iraq and the Levant (Isis) were behind the abduction.

Sushma Swaraj, minister for external affairs, said on Thursday she was monitoring the situation and all efforts will be taken to free the hostages.

"I'm personally supervising efforts. Will leave no stone unturned to ensure rescue of our citizens."

Swaraj is scheduled to meet the family members of the abducted workers, most of whom are from the northern state of Punjab.

The chief minister of Punjab state, Parkash Singh Badal, said his government was ready to meet any ransom demands made by the abductors.

"The government should do the maximum. If they want any, I don't know whether I should say or not, ransom or anything, the Punjab government is ready to pay all that," he said, according to CNN-IBN.

Confusion has prevailed ever since news broke that Indian workers were under Isis captivity.

Nobody has claimed the abduction, and there is no clarity about where the hostages are held.

However, a relative of one of the abducted men has said there is confirmation that Isis was behind the incident.

"I have got news that Isis is keeping my relatives safe. The last time I spoke to my relatives was on June 15, till then they said they were safe. They are saying they will only hand over my relatives to the Indian government or the company they are working for," the person said, according to CNN-IBN.

New Delhi has sent a senior diplomat to Mosul to help establish communication with the militia and expedite the rescue process. The government has also reached out to the International Red Cross to help find the workers.

It has been confirmed that the abducted people were working for the Tariq Noor al Juda construction company in Mosul.

India's external affairs ministry also said Iraqi authorities have confirmed the abduction of the workers.

The Isis militants who aim to create a Sunni Islamic caliphate straddling Iraq and Syria launched their audacious campaign with the capture of the northern city of Mosul ten days ago and have since then ripped through government defences in much of northern Iraq.

According to accounts by the relatives of the abducted men, the company officials fled as the violence escalated, leaving the workers stranded. Most of the workers did not have their passports with them as the documents were submitted to their employers.

"We are hearing all sorts of news from Iraq, visuals on the television are frightening and we are very worried about him," said a relative of one of the kidnapped men, according to the Hindustan Times.