Allahabad Police resorted to lathicharge to disburse the protesters after both the parties filed complaints against each other during campaigning, sources said.
"The incident took place in Mutthiganj police station area when a cavalcade of supporters of the MP Kunwar Reoti Raman Singh was passing in front of the election office set up by Nand Gopal Gupta Nandi.
"While the MP has alleged that they were attacked by Nandi's supporters the latter claimed that violence was initiated by the other side," Inspector in-charge of Mutthiganj police station Indrajeet Chaturvedi said today.
A number of Nandi's supporters and his wife Abhilasha, who is the city Mayor, received minor injuries in the incident.
Later, the couple marched to the police station where their supporters got into a heated argument with policemen and indulged in stone-pelting which left a number of local police and paramilitary personnel injured, Inspector Chaturvedi said.
Meanwhile, a spokesman in the district police headquarters said that a case has been registered against the MP and his supporters under various sections of IPC relating to rioting and affray, though no arrests have been made in this connection so far.
A complaint has also been lodged by Reoti Raman Singh against Nandi at the Mutthiganj police station.
Besides, Inspector Chaturvedi said, "we are going to lodge a separate case against Nandi and his supporters for the stone-pelting at the police station".
Following clashes, heavy police personnel has been deployed in the area to avoid any untoward incident.
Allahabad goes to polls on May 7.
Ruling Samajwadi Party's Reoti Raman Singh is the sitting MP from Allahabad, where polling will take place on May 7.
AAP, RSS clash in Varanasi
Meanwhile, another serious clash broke out between AAP volunteers and members of RSS in Varanasi on Saturday, police told reporters.
According to BJP and RSS workers, AAP members started pelted stones at the RSS office. Agitated RSS workers retaliated by pelting stones at AAP workers.
AAP members, however, claimed that they were attacked by the BJP workers while they were passing by the RSS office.
The RSS unit has filed an FIR at the Lanka police station in this regard.
(With agency inputs)