A six-year-old girl from Singhpura Munnan village in Moga district was raped, Senior SP (Moga) S S Grewal said.
The accused Soni Singh took the victim to his place about 20 days back and raped her, Grewal said, adding that Singh had confessed to the crime about which police came to know only on Monday.
The accused has been arrested, the SSP said. Medical examination of the girl confirmed rape.
In a separate case, an eight-year-old girl of a migrant labourer was allegedly raped and killed by a 25-year-old youth at Simbli village in Hoshiarpur district.
Mehtiana police booked a youth, Sanjay Kumar, of district Purnia (Bihar). The accused is at large.
Both, Kumar and the victim's family, were living at a farmhouse in Simbli village.
On Wednesday, the girl's body was found in nearby fields.
In the third incident, a 14-year-old girl was allegedly gang-raped by three persons at Talwandi Kalan village on the outskirts of Ludhiana city.
Police Commissioner Ishwar Singh said that all the accused, aged between 28 to 30 have been arrested.
In reply to a question, the Commissioner said that investigations and medical check-up of the victim have been carried under the supervision of a lady IPS officer Jagdambey Nilambri.
In another crime against women, three villagers were on Wednesday booked on the charge of teasing and beating up a woman of the same village.
The accused Ladoo, Sonu and Kaka, all residents of Bassi Mustafa village were booked.
The girl alleged in her complaint that while she along with her sister was returning home from work, the accused first teased her and then later thrashed her up.
In another case, police on Tuesday booked ten persons in connection with the alleged abduction of two sisters at Jalala village of Hoshiarpur district.
The accused went to the victim's home on the night of December 29 and allegedly kidnapped them, police said.
The Punjab Police has decided to constitute specialised investigation teams to deal with sexual assaults on women, official sources said in Chandigarh.
The Sexual Assault Response Teams will comprise women in combat wing and men in the administrative roles. Rape cases will be reported to the headquarters on the same day and women constables will record statements of victims.
Meanwhile, a 20-year-old woman from Karnal, who had accused her neighbour Pardeep of raping her since June last year, died at a hospital at Rohtak on December 29 after delivering a still born child, police said. Pardeep has been arrested on charges of rape.
The victim died after developing post-delivery complications, police said. The DNA sample of the stillborn child will now be matched with the DNA of the accused.