Kolkata, May 26 (IANS): Admitting she once had a "penchant" for seeking CBI probes, West Bengal Chief Minister Mamata Banerjee on Tuesday accused the central agency of taking up cases which suits it politically.

Speaking at the state assembly, Banerjee also blamed the central government's interference for the the killing of a Railway Protection Force (RPF) constable during an anti-hawker drive in Malda.

Questioning the CBI's efficiency in several cases including the theft of Nobel medallion of poet Rabindranath Tagore, Banerjee said: "They (CBI) do what suits them politically."

The CBI, which has arrested and interrogated several Trinamool leaders while probing the multi-crore rupee Saradha scam, is facing regular attacks attack from Banerjee and her party peers.

She also said her "penchant" for seeking a CBI probe into incidents was changing and claimed that the agency refused to take up as many as 14 cases including the rape of nun in Ranaghat, that she had referred to the central agency.

A septuagenarian nun was allegedly raped inside a convent in Ranaghat of Nadia district earlier in March.

Referring to the Malda incident where an RPF constable S. Samanta was stoned to death by angry hawkers in Malda Town railway station, Banerjee said it was a result of central government 's interference in the state's matters and asserted that the central government should have given the state government a prior information about the anti-hawker drive.

She said the hawkers' economic condition was "miserable" and they should not be evicted in an unplanned way.

The Banerjee government earlier announced legalizing hawking in the state and issuing trade licenses to hawkers.

She also charged the opposition - the Communist Party of India-Marxist, the Bharatiya Janata Party and the Congress - with forging an understanding and colluding against her Trinamool Congress.