Of the two bombs that were hurled, the second one exploded killing the constable, who suffered head injuries, on the spot, the official said.
The clashes broke out in the Shyamnagar area in the evening during a rally led by BJP MP Arjun Singh over alleged corruption in cyclone relief distribution, they said.
The lawyer identified as Sanjeev Lodhi, who also holds a post in the Lucknow Bar Association, suffered minor injuries in the attack.
When the accused, Zalim Singh, found his wife, Komal, talking to one Manoj near a house where the woman is residing after leaving her husband’s place, Singh hurled the bombs at them.
Chief Minister Mamata Banerjee is said to have had a word with Pastor Anup Kumar Ghosh and assured of all possible support.
Authorities went into a tizzy following the incident as the city and nearby coastal town of Mamallapuram is under a thick security blanket in view of the visit of Chinese President Xi Jinping on Friday.
60-year-old Gulab Gupta and his grandson son Samrat were hit by the bombs while they were waiting for the child's school bus outside their house in Manu Ka Purwa locality on Thursday.
Police have taken 10 BJP-RSS workers in custody, in connection with the country-made bomb attack in Panoor. They have also seized a few vehicles and mobile phones for further investigation.
The GRP stopped the train at Akbarganj Railway Station for checking after it received information about a bomb on the Amritsar-bound train.
The men -- reportedly two Lebanese-Australian fathers and their sons -- were arrested in raids across Sydney on Saturday evening.
The roof of the house where he was "making" the bomb was destroyed in the blast.
Sheikh Hafizul (24) and his elder brother Shiekh Tariq Hussain (27) were killed on the spot when a bomb exploded in their house in the wee hours, Superintendent of Police Mukesh Kumar said.
Initial reports suggest that the explosion happened when the labourers were trying to clean up vacant spot inside the factory which was covered with bushes.
Over 200 crude bombs, hand grenades and revolvers have been seized during police raids at Belsore village in Burdwan district since Saturday night.
Four unidentified men came in on a bike and hurled two country made bombs at the office.
While some eyewitnesses claimed a woman was carrying the bomb but police officials say they cannot confirm the same.
West Bengal police on Tuesday morning recovered over 200 crude bombs in Birbhum district of West Bengal. Two people have been arrested in connection to the recovered crude bombs, the police informed.
The bomb went off when it was being removed in a hurry during a police raid.
The incident occurred in a room located above a medical shop.