Chennai, July 27 - The Bharatiya Janata Party (BJP) Monday announced its candidates for the forthcoming by-elections for five assembly constituencies in Tamil Nadu that is now set to be a four-cornered fight with the DMDK deciding to contest on its own.

Actor-turned-politician Vijaykanth's DMDK had Sunday announced it decision the fight the polls alone and had named its candidates.

Now the state's ruling DMK-Congress combine will cross swords with the DMDK, Bharatiya Janata Party (BJP) and the two Communist parties -- Communist Party of India-Marxist (CPI-M) and the Communist Party of India (CPI).

Earlier the major opposition party AIADMK and its allies -- MDMK and PMK -- had decided to boycott the by-polls next month, alleging that the elections would not be free and fair.

AIADMK chief J. Jayalalithaa has asked her party cadres to not vote in the elections.

The constituencies for which by-polls are to be held Aug 18 are Bargur, Thondamuthur, Cumbum, Illayangudi and Srivaikundam.

The ruling DMK will contest in Bargur, Illayankudi and Cumbum and has named its candidates while its ally Congress will field its candidates for Thondamuthur and Srivaikundam seats.

The Communist parties will contest only four seats and support a friendly party in the fifth one.

While the CPI-M will contest in Thondamathur and Cumbum constituencies, CPI will test its strength in Srivaikumdam and Bargur.