Three children were killed in east Nepal on Sunday while playing with a crude bomb left by suspected Maoist rebels, police said. Police officer Tapendra Dhoj Hamal said the dead were aged between eight and 14 years. Another three people were wounded in the explosion in Janakpur, 380 km (240 miles) east of Kathmandu. Hamal said the Maoists, fighting to replace Nepal's Hindu monarchy with a communist republic, may have left the bomb during a raid on a police post in the area. Rights groups say at least 375 children have died in the Maoist conflict that began in 1996. Police detained at least seven activists in Kathmandu on Sunday as they protested against King Gyanendra's seizure of power last month and called for restoration of political freedom. Witnesses said the activists, including former legislators, were picked up from the heart of the Nepali capital as they shouted anti-king slogans and waved the Nepali Congress party flags, ignoring a ban on protest rallies. "Restore democracy" and "Withdraw the royal proclamation of emergency", the protesters shouted as riot police detained them. King Gyanendra fired the government, assumed absolute powers in the Himalayan kingdom and put political leaders under house arrest or in jail. He said the move was necessary to crush the nine-year Maoist revolt in which more than 11,000 people have died.