Rasu Miah's first victim was the wife of his brother-in-law whom he said he raped before strangling her in 2007, police officer Mir Kashem said.
Kashem said Miah said he went on to kill another 10 women, aged between 17 and 35. His last victim was a woman found dead in her village in eastern Bangladesh in July this year. He did not say he killed the woman who refused to marry him.
Police brought Miah in for questioning Wednesday about the theft of a ceiling fan from a mosque and in the course of the interrogation asked him about the death of a woman in the area whose number was on his cell phone. But it was only later, while answering questions Sunday in court about the theft, that he confessed to the 11 murders, Kashem said.
Miah told a magistrate in his home town of Chandpur, 40 miles (65 kilometers) east of the capital, Dhaka, that 15 years ago he decided to kill at least 101 women after a woman he loved refused to marry him. He denied, however, killing the woman whose number he had.
The 40-year-old is married and has three sons and one daughter.
"Even though I started a family, I've never forgotten my vow," Miah told the magistrate. "I began my mission in 2007 and since then I've killed 11 women."
Miah said he lured all of his victims _ most of whom were from poor families _ to Chandpur with offers of marriage before killing them, said Kashem, who is part of the team investigating the crimes. Miah did not say if he raped all of the women.
Kashem said police have arrested him for the murders and are questioning him.
Police had recovered the bodies of all Miah's purported victims from rivers or canals, and they had been buried without being unidentified.