Suspected Maoist rebels in India abducted 15 workers from a bridge construction site in poverty-ridden Bihar, one of the many hotbeds of the leftwing insurgency, police said on Wednesday.
About 50 armed guerrillas ambushed the site on Tuesday, local district police chief R.N. Singh said.
He said police suspected that the company building the bridge had refused to pay money to the Maoists, who are often accused of extortion.
Senior officials in Patna said that efforts were on to rescue the 15 hostages.
The latest attack followed the slaughter in July of six men in Bihar by Maoists who raided a village wearing police uniforms and opened fire.
The Maoist movement, which began in 1967, feeds off land disputes, police brutality and corruption, and is strongest in the poorest and most deprived areas of India, many of which are rich in natural resources.
Prime Minister Manmohan Singh has called the insurgency India's main internal security threat.