KATHMANDU, Oct 30 (Reuters) - About 200 Nepali journalists protested in Kathmandu on Tuesday against the kidnapping of a reporter who wrote articles critical of Maoist guerrillas. Media groups and a parliamentary panel have blamed the abduction of Birendra Sha from the country's southern plains early this month on the Maoists. But the former rebels, who signed a peace deal with the government last year, deny any involvement and have formed their own panel to investigate the charge. Some of the protesters pinned Sha's photograph to their chest and marched near the parliament building in Kathmandu. Mainstream political parties accuse the Maoists of continuing with kidnappings and extortion despite ending their decade-old anti-monarchy conflict which caused more than 13,000 deaths.