Patna: Train and road traffic in Bihar was badly hit on Monday by a shutdown called by the CPI-ML to protest the Class 12 toppers' scam and push for a judicial inquiry into it. Activists of the Communist Party of India-Marxist Leninist (CPI-ML) squatted on rail tracks, bringing trains to a halt in Patna, Jehanabad, Darbhanga, Nawada, Bhagalpur, Gaya, Bhojpur, Madhubani, and Muzaffarpur districts, police officials said. "CPI-ML supporters stopped about a dozen long-distance trains at various railway stations across the state. Train services have been disrupted due to the shutdown since Saturday morning, leaving hundreds of people stranded at railway stations," a railway official said. Thousands of CPI-ML supporters have been enforcing the shutdown since early Monday morning. Road traffic was also hit in Patna, Aurangabad, Jehanabad, Gaya, Darbhanga and Bhojpur in particular, a police official said. The protesters reportedly blocked national and state highways. The activists of the CPI-ML, the All India Students' Association (AISA), and the All India Progressive Women's Association (AIPWA) also held demonstrations, shouting slogans and demanding a judicial inquiry into the toppers' scam. CPI-ML state secretary Kumal told reporters that the state government led by Chief Minister Nitish Kumar was responsible for the toppers' scam, which refers to corruption in the conduct of Class 12 examination by the Bihar School Examination Board (BSEB). The scandal surfaced when a sting done by Aaj Tak TV channel showed two Class 12 'toppers' giving ludicrous answers to some elementary questions about the subjects they 'topped' in. The police has so far arrested about 20 people in connection with the scam.