Kolkata: Seven persons including a polling officer were injured in three separate incidents of violence at the start of the panchayat elections in Murshidabad, North 24 Parganas and Jalpaiguri districts of West Bengal on May 11.

State's DIG police (head quarters) N C Ghosh said five Communist Party of India-Marxist (CPM) activists and one Revolutionary Socialist Party (RSP) worker were injured in an armed clash outside a polling booth at Shamuktala in Jalpaiguri district.

The condition of two injured persons belonging to the CPM was stated to be critical, Ghosh said.

Forty-nine persons have been detained in this connection, he said.

In a separate incident, one polling officer sustained splinter injuries at Madanpur under Barasat sub division in North 24 Parganas district when some miscreants hurled bombs at a polling station.

The polling was temporarily suspended due to the incident, the DIG said.

Five persons were arrested after CPM and Congress workers clashed with bombs before a polling booth at Beldanga in Murshidabad district.

Polling, however, was not affected due to this incident, Ghosh said.

These apart, polling for the three-tier Panchayat system in 17 districts of the state was "by and large peaceful", the DIG said.

PTI