Seven men involved and in connection with Cambodia's school hostage crisis in Siem Reap were charged by prosecutors with murder and kidnapping on Sunday.
Bou Bunhang, chief deputy prosecutor in Siem Reap province, said the four hostage-takers were charged with four crimes.
"We have charged the four with illegal detention of persons, kidnapping for ransom, deliberate killing people and using illegal weapon," he told reporters.
And the three other men, who were arrested as accomplices after the incident, were facing with the same charges as the four, except illegal detention of people, he said.
If found guilty, the seven will be sentenced to 15 years in prison or life imprisonment.
At least four masked men, armed with a pistol, entered Siem Reap 's international school and took about 30 students aged 2 to 6 as hostage on Thursday. They demanded money, weapon and a vehicle in exchange for the release of the hostage.
After about six-hour standoff, the four were arrested by police at the scene, but a 2-year-old Canadian boy was killed by the bandits.
Chea Sokhom, 23-year-old, said during inquesting that he wanted to kill two children of his former South Korean boss who had attacked him.
Chea Sokhom worked as a driver for South Korean restaurateur's two children in Siem Reap. Chea said about two months ago, the boss slapped his face twice for his late, he then had a grudge against him and planned to revenge.
Nearly 30 years' civil conflict in the Kingdom made it awash with illegal weapon, though the government has made great efforts to destroy them. Since 1999, the government has destroyed more than 150,000 weapons.
Siem Reap, located more than 300 km northwestern of Phnom Penh, is home of world famous Angkor Wat temples and the main destination of the foreign travelers. In 2004, more than 1 million tourists visited Cambodia.
And with a boom of tourism industry, more and more foreigners arrived here to invest and work in tourism service industry.
Source: Xinhua