Terrorists set off seven bombs yesterday, killing three girls and wounding a boy, despite a security force of more than 100,000 men deployed on the last day of the Punjab state election campaign, The Associated Press reported.

United News of India said all the bombs were planted in vehicles used by campaign workers or candidates in Wednesday's election for the 115-member state legislature and 13 seats in Parliament. Campaigning is prohibited on the day before the election.

More than 115,000 police and paramilitary forces were stationed throughout the troubled northern state because of fears that terrorists would try to frighten the 10.7 million voters away from the polls.

Police said the three teen-age girls were killed in Batala, a stronghold of Sikh militants in the northernmost Gurdarspur district, by a bomb that blew up a car used by two members of Parliament from Prime Minister Rajiv Gandhi's Congress (I) party.

The Parliament members, who had attended a campaign rally, left the car five minutes before the explosion, one of them said.

In the southern district of Faridkot, another militant stronghold, one boy was slightly injured in a bomb explosion, the Indian news agency said. No deaths nor injuries were reported in the five other blasts.