Gurgaon, Feb 27 (IANS): Four men have been arrested here for killing a 37-year-old woman during a robbery attempt Feb 21, police said Thursday.

Amit Kumar alias Rinku, Promod alias Bijli, Sona Lal and Ranjit - all in the age group of 22-28 - were living in rented accommodation in Khandsa village.

Amit hails from Kanpur, Uttar Pradesh, while the other three are from Bihar. Promod works as a labour contractor while the others are labourers.

"The arrests were made from Sector 5 area based on evidence collected by the crime branch," Gurgaon police commissioner Alok Mittal told reporters.

Two pistols and 19 cartridges were seized from them.

Police had earlier announced Rs.50,000 as reward for information leading to the arrest of the accused.

Amit worked as a labourer at the house of now deceased Sanjeeta Hooda in Sector 4 and was familiar with the family's activities, police said. He then plotted a robbery with others.

On Feb 21, Hooda's mother-in-law Sumitra saw some people running out of their house when she returned from her morning walk. She confronted the robbers but was attacked and injured.

She cried for help and some people chased the attackers but they managed to flee.

Her daughter-in-law Sanjeeta was found with her hands and legs tied to a bed and her mouth gagged. The woman was rushed to a hospital but was declared dead.

The police did not say what was stolen from the house.