Solanki, also the minister for fisheries and the only member of Koli community in the state Cabinet, tendered his resignation to express solidarity with his community.
Two girls of the Koli community had gone to Datar shrine in Junagadh on May 13 with their families, when they were abducted by two men, who allegedly raped one girl and murdered another when she resisted them.
Solanki's resignation in the election year will be a blow to the BJP, which has been enjoying the support of the Koli community for the last 15 years.
The Kolis are one of the powerful OBC communities in Gujarat and their vote can tilt the balance in at least 20 assembly constituencies.
Solanki first submitted his resignation to the leaders of his community at his official residence in Gandhinagar amidst hundreds of people of the community.
Then he along with his supporters went to the bunglow of Minister of State for Home Amit Shah to present the resignation to party general secretary Jayanti Barot.
After coming out of the house of Shah, Solanki said he has submitted his resignation. He left for his hometown Dhanduka in Bhavnagar district after submitting his resignation.
The murder and rape of the girls has turned into a major political issue in the state. The Congress has organised sit-ins and demonstrations at various places in Saurashtra, where the community population is concentrated.
The BJP on the other hand accused the Congress of taking political advantage out of the incident.
Four Gujarat State Road Transport Corporation buses were burnt by angry members of the Koli community on Tuesday on the outskirts of Rajkot.
