Gurgaon, Jan 30 (IANS): Five members of a family residing at Sector 31 of Gurgaon were Thursday attacked and robbed by unidentified assailants, police said.

Sixty-five-year-old Shyam Kumar, his wife Shagun, son Rajat Kumar, daughter-in-law Anuradha and grandson Pradun, about three years old, were present in the house when a gang of four to five masked men armed with knives broke in at about 3 a.m. Thursday, police said.

"The masked men carried knives and iron rods. They attacked the family members, who were sleeping, and looted jewellery, cash and other valuables," a senior police officer told IANS.

All five members of the family were injured in the attack.

The condition of Shyam Kumar was stated critical. The injured shocked victims were admitted to a private hospital.

Kumar's son Rajat works as an architect, and his daughter-in-law is a lawyer.

A case under Section 379 (theft) and 459 (grievous hurt caused during house-trespass or house-breaking) of the Indian Penal Code was registered at the Sector 40 police station in Gurgaon.