In the incident that took place late on Thursday night, cash and jewellery worth Rs 50,000 belonging to the victims, was also looted, police said.
According to police, members of four families, hailing from Garbada in Dahod district, were sleeping inside their temporary plastic tents near the construction site located about a kilometer away from Hansalpur village.
Between 11 pm and 12 am, around seven unidentified men came to the spot and woke up the sleeping persons, police said. "The assailants then separated the males from women. They held the men and children hostage and intimidated them," police said.
Police said the men then raped the three women and a minor girl one by one some distance away from the tents. The accused also decamped with booty worth Rs 50,000, including Rs 30,000 in cash and silver jewellery worth Rs 20,000.
Deputy Superintendent of Police Girish Pandya said, "We have lodged an FIR and are investigating from all angles. We will get details about gangs which use such modus operandi within a day or two and proceed with further probe." "Also, similar cases in neighbouring districts are being studied to zero in on the suspects. Villagers say this is the first such loot-cum-rape incident in the entire village. They have lent their support to the police investigation," Pandya said.
The police, who rushed to the spot, said the victims were given medical treatment and a couple of police officials have been deployed at the site to protect the victims.
Police said the prime motive of offenders seems to be robbery. Before raping them, the assailants searched women and found Rs 30,000 cash with them. The families had received the cash as wages a couple of days for some work that they did in Sanand area.
A year and a half ago, in July 2011, two women, who were working near Chekhla village at a construction site had been raped and robbed in a similar fashion in Sanand, they said.
According to the police, there are several gangs operating in the district, who, after robbing people, also rape the women so that they don't approach the police.