Unknown assailants have kidnapped 40 Indian construction workers from 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 is unknown, foreign ministry spokesman Syed Akbaruddin told a news briefing. No ransom demand has been received.
"The Red Crescent confirmed to us that as per their information, 40 Indian construction workers have been kidnapped," Akbaruddin said.
Islamist militants have long considered India a target. An al Qaeda video released last week called on Indian Muslims to follow the example of Syria and Iraq and launch a jihad, or holy war, against the government.
Most of the hostages are from the north Indian state of Punjab and were working for a Baghdad-based company called Tariq Noor Al Huda, Akbaruddin said.
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 are working 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. It 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 swept through the Tigris valley towards Baghdad.
Scores were killed on Tuesday in a battle for a provincial capital close to Baghdad, and fighting shut Iraq's biggest refinery at Baiji, hitting fuel and power supplies.
Sunni militants have taken control of most of Iraq's largest oil refinery, located in Baiji in northern Iraq, an official at the refinery said on Wednesday.
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"The militants have managed to break in to the refinery. Now they are in control of the production units, administration building and four watch towers. This is 75 percent of the refinery," an official speaking from inside the refinery said.
He says clashes continue near the main control room with security forces.
U.S. President Barack Obama is considering military options to push back ISIL, a splinter group of al Qaeda that prides itself on its brutality and has boasted of massacring hundreds of troops who surrendered.