She also described the killings of the members of the Gond tribe as "massacre".
Late on Friday, some government officials also arrived at the Chunar guest house to ask the Congress leader to return to Delhi. However, she remained adamant.
"The Uttar Pradesh government has sent ADG Varanasi Brij Bhushan, Varanasi Commissioner Deepak Agarwal, Commissioner Mirzapur and DIG Mirzapur to tell me that I should return without meeting the victims' families. They have not given me any reason or documents for detaining me," Gandhi said in a tweet.
"I have made it clear to them that I have not come here to break any law but to meet the families and I won't return without meeting them," she said.
The officials then left the guest house at around 1.30 a.m.
Earlier on Friday, Priyanka Gandhi refused to fill the bail bond of Rs 50,000.
"I have not done anything wrong and so I will not fill the bail bond. District administration and the government is free to send me to jail if they want," she said.
She has said that the administration informed her that she was detained under section 107/116 of the CrPC.
Gandhi was detained at the Chunar Guest House here after she was stopped from going to Murtiya village in Sonebhadra district. The police denied that she had been arrested.
The Congress leader arrived in Varanasi on Friday morning and met the injured persons admitted to the Trauma Centre of the Banaras Hindu University. When she proceeded towards Sonebhadra, her convoy was stopped on the Mirzapur border.
A defiant Gandhi then squatted on the ground with the Congress workers and was later taken away in a government vehicle to Chunar.
At least 10 people, including three women, died and over 24 were injured in a clash between Gond and Gujjar communities over a land dispute in Sonebhadra on Wednesday.
Even while she remained under detention, scores of Congress workers and locals gathered at the guest house to meet her with whom she held discussions on several issues.
The police have arrested 29 people, including the kingpin Yogesh Dutt, in connection with the violence in Sonebhadra. A case has been filed against 78 people.
( With inputs from IANS )