At least seven people were killed and several others injured in clashes between supporters of the Communist Party of India � Marxist and the Congress in Murshidabad and Birbhum districts, as polling for the third and final phase of the Panchayat elections was underway in seven districts of West Bengal on Sunday.

Inspector General of Police (Law and Order) Raj Kanojia said two CPI-M and two Congress supporters were killed at the Domkol police station area of Murshidabad district while one person each was killed at the Harudanga and Raninagar police station areas in the same district, as rival party supporters clashed with bombs and firearms.

He said that one CPI-M worker was killed at Nannur in Birbhum district.

Altogether 62 people were arrested in Murshidabad district, the stronghold of the Congress.

Following violence in the second phase, security has been beefed up for the third and final phase of the Panchayat elections, which is being held in districts of Coochbehar, Jalpaiguri, North and South Dinajpur, Birbhum, Murshidabad and Malda.

The first phase of polls, held on May 11, was by and large peaceful. But six people were killed and at least 15 injured in poll related violence during the second phase of polling on May 14.