The families engaged in construction work in Jalalabad village at Muradnagar were looted of cash and jewelery worth Rs 4 lakh by the gang on Thursday, SP (Rural) Rakesh Pandey said.
A woman from one of the families was raped by robber Praveen (30), he said.
Seven members of the gang, including Praveen have been arrested, Pandey said.
The woman has been sent for medical examination.
The gang was apparently hired by a nearby farmer to chase away wild pigs from his fields, police said.
Efforts are on to arrest the remaining culprits, they added.