New Delhi: The picturesque hilly state of Sikkim is poised for a direct rail link with the rest of the country within the next five years, with Railways terming the project an engineering challenge in itself.

Most of the rail link, which will run through tunnels will have bridge piers that will surpass Qutub Minar in height, sources in Railways said here on Monday.

Work on the ambitious Rs 3,300 crore project began last month by Ircon International Limited, which is also involved in the Kashmir rail link project.

Sources said the project "poses major challenge in execution and will be considered a rare engineering achievement on its completion."

The proposed 44.4 km railway line passes through the foothills of Kanchanjungha mountain range and Teesta river valley, with the alignment running from Rangpo in Sikkim to Sevok near Silguri in north of West Bengal
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Vice President Hamid Ansari and Railway Minister Mamata Banerjee had laid the foundation of the project in October last year.