The BJP President said he agreed with Ms Banerjee's contention that Delhi was not a safe place and attacked the Congress-led UPA government over the situation in the national capital which, he said, was "slipping into a state of anarchy with each passing day".
"Whatever has happened with Mamataji and (West Bengal Finance Minister) Amit Mitra, I condemn it strongly. In clean politics, it is expected that if any political party or organisation wants to lodge its protest on an issue, there is a way to do so. But if anyone tries to lodge its protest by taking to violence, I feel the government should take stern steps against them," Mr Singh said.
"Delhi is slipping into a state of anarchy every passing day. When Chief Ministers and Finance Ministers are not safe in Delhi, then one can imagine how the common man will remain safe. I demand that there should be a proper investigation and action on this issue," he said.
The BJP chief alleged that situation in Delhi, under the Congress-led UPA government, is such that even Chief Ministers and Finance Ministers didn't feel safe.
BJP leaders have been trying to reach out to the Trinamool chief in a bid to win her over ahead of the next general elections.
Gujarat Chief Minister Narendra Modi had, on Tuesday, commended Mamata Banerjee government while addressing top Bengal industrialists in Kolkata.