Nepal's former Maoist rebels on Saturday observed the 20th anniversary of the start of their armed campaign that eventually led to the Himalayan nation's transition from a Hindu kingdom to a secular republic even as it grapples with its current political turmoil. Hundreds of Maoist cadres and leaders held rallies in here commemorating the so-called 'People's War', the decade-long insurgency that began in 1996, killing over 16,000 people.