DEHRADUN: The concluding session of a three-day international workshop on tigers was abruptly cancelled on Friday following protests by residents of 14 different villages in Sunderkhal forest under the Corbett National Park Official sources said the protests also led to the cancellation of Union forest minister Jairam Ramesh 's visit. The minister was to address the concluding session of a workshop which began on March 9 to mark the completion of 75 years of Corbett Tiger Reserve The protesters locked the gates to prevent over 25 tiger experts from India and abroad from entering the venue. As senior CTR officials' requests were ignored, the officials had no option but to cancel the workshop.