West Bengal Chief Minister Mamata Banerjee today asserted that Darjeeling Hills would remain part of West Bengal, even as a section of Gorkha Janmukti Morcha supporters raised slogans demanding a separate state during inauguration of North Bengal Festival.

"Let us remain together, Darjeeling is part of Bengal and we will remain together," Banerjee said at a colourful programme at the picturesque Mall here in the presence of GJM president and Gorkhaland Territorial Authority (GTA) chief executive Bimal Gurung.

"There should not be further trouble as that would hamper development again," she said while addressing the gathering.

But things went awry as a section of GJM supporters raised slogans and displayed posters demanding Gorkhaland at the fag end of her brief address.

A visibly angry Banerjee stood up and warned protesters not to raise such political slogans at the programme and asked them to do so at party forum.

"Please remember this is not a party programme, this is a government programme. I am very rough and tough in such issues," the chief minister warned.

"You are free to give political slogans at party programmes, but this is a government programme and such slogans cannot be raised here," she said.

"Please do not give wrong message so that people will think Darjeeling is again going for problem," Banerjee said as Gurung sat beside her on the stage.

Banerjee then left the stage and went on to sit among the spectators even as the GJM supporters were waving their green, white and yellow-coloured party flags.

Earlier, addressing the gathering, the chief minister said, "I have come to Darjeeling as no one in the last 20 years came here."

Referring to the previous Left Front government's alleged failure to ensure development of the Darjeeling Hills and failure of the then chief minister to visit the area, Banerjee said, "If Darjeeling remains peaceful, development work will continue and employment will be generated."

Nothing had happened in previous several years except for politics, she said.

Asserting that the Hills will remain within West Bengal, she said several new tourist spots like Lamahata or Sandakfu had been developed or were being decked up.

"Helipads, airports and other world class facilities will be made available and after that tourists from all over the world will flock to Darjeeling," she said.

She announced that Rs 80 crore had been sanctioned for National Highway 55, the lifeline to the hills from Siliguri in the plains.

Also two hydro-power projects were coming up at Teesta and Rimbhi besides various development activities in Darjeeling and other hill sub-divisions of Kurseong and Kalimpong, she said.

"There should not be further trouble as that would stop development again," Banerjee cautioned.

"Darjeeling should remain peaceful, I have been hearing some things for some time, but I want to tell you that peace be maintained for development," she said referring to the GJM's fresh attempt at raising the Gorkhaland issue.

GTA, a semi-autonomous body for Darjeeling Hills, was formed in 2012 in a tripartite agreement involving the Centre, West Bengal government and the GJM. The first election to the body was won by the GJM.