In Himachal Pradesh, opposition Congress staged a walkout in the state assembly today demanding proper investigation into the school education board examination scam that rocked the state in September. The scam came to light when a Class 10 student claimed that he got a pass certificate without appearing in the examinations. Police found that 208 students, who appeared as private candidates in the exams in March for Classes 8, 10, 11 and 12, secured first class without ever appearing for the tests. Raising the issue in the assembly, Congress legislators Kaul Singh Thakur, Vidya Stokes and Harsh Vardhan said that the government is trying to shield the main accused persons and so far arrested only on petty employees. They demanded action against top board officials, including then board chairman C.L. Gupta, who retired in October, and board secretary Prabhat Sharma for their failure to check the scam. Replying to the debate, Education Minister I.D. Dhiman said the government has already started an inquiry and guilty would not be spared.