The Congress bagged the Bharmour, Lahaul-Spiti and Kinnaur seat in the assembly by-polls in Himachal Pradesh.
The polling in these seats had been postponed, as they were snowbound in February, when the rest of the state went to the polls.
In Bharmour its candidate Thakur Singh defeated his nearest Bharatiya Janata Party rival Tulsi Ram by a margin of 8,000 votes. Thakur Singh polled 21,869 votes against Tulsi Ram's 12,177.
In Lahaul-Spiti, its candidate Raghubir Singh defeated Himachal Vikas Congress candidate and former minister Ram Lal Markandey by 4,768 votes.
Raghubir Singh polled 9,458 votes against HVC candidate's 4,690 votes.
In Kinnaur, its candidate Jagat Singh Negi defeated BJP's Tejwant Singh by a margin of 7,406 votes.
The Congress' strength is now 43 in a House of 68 members. BJP has 16
members, Himachal Vikas Congress has one, Himloktantrik Morcha one, Lok Jan Shakti one and six have won as independents.
Meanwhile, in West Bengal, the ruling Communist Party of India wrested the Nabadwip Lok Sabha seat from opposition Trinamool Congress and retained the Vidyasagar assembly constituency as well on Wednesday.
The by-elections to both seats were held Sunday.
Alokesh Das defeated Trinamool's Abir Mohan Biswas by about 98,000 votes in the Nabadwip seat in Nadia district.
The Nabadwip seat felt vacant after the death of Trinamool MP Ananda Mohan Biswas. Eight candidates were in the fray.
In the Vidyasagar assembly constituency in the city's north, CPI-M's Anadi Sahu defeated his Congress rival Mahua Mondal by about 22,000 votes in an eight-cornered contest.
The seat had fallen vacant after the death of CPI-M's Laxmi Dey.
Mondal is the daughter of former union minister and expelled Trinamool Congress leader Ajit Panja.
With inputs from M Chhaya in Kolkata