Ferozepur, June 26 -- Four persons sustained gunshot injuries outside the centre where the nomination filing process for the Mamdot nagar panchayat elections was being carried out on Thursday, police said. The injured were initially taken to the civil hospital, from where they were referred to Guru Gobind Singh Medical College and Hospital in Faridkot, officials said, adding that one person was detained. The polling for the 13 wards of the Mamdot nagar panchayat is slated for July 5. Thursday was the last day for filing nomination papers so candidates in large numbers had gathered outside the returning officer's office when the violence broke out. Political activist Gurpreet Singh Sekhon, who is supporting a few candidates, blamed Congress workers. "They resorted to stone-pelting before opening fire on my supporters. Several of our supporters were injured," he said. Rubbishing the charge, Punjab Pradesh Congress Committee member Ashu Bangar said Sekhon's supporters tried to vitiate the atmosphere as they opened fire on Congress workers. SP (investigation) Manjit Singh said the clash erupted after an argument between two groups. "Police personnel, including a DSP and SHOs, were deployed. The incident occurred around 100 metres away from the nomination centre," he said. "CCTV footage and videos are being examined," he said. Police said an FIR would be registered on the basis of an investigation....