Earlier in the day a bomb exploded outside the headquarters of the royalist FUNCINPEC party in Phnom Penh on Sunday while two hand grenades were found outside the royal palace, police said.

However police brushed aside the incident as insignificant adding there were no casualties in the explosion, and polling was not disrupted.

A short time later two hand grenades were found near the entrance outside the royal palace but had not detonated, a police spokesman on the scene said.

"According to the law, we have closed the polling stations nationwide," National Election Committee chairman Im Suosdey told reporters.

"Everything has gone according to schedule and even though there were some (technical) problems, we fixed them on time," he said.

"Everything has gone according to schedule."

--National Election Committee chairman Im Suosdey

 Cambodians went to the polls after a boisterous but relatively bloodless general election campaign marking another step in the young democracy's long journey from the 1970s Khmer Rouge genocide.

More than 6.3 million people were registered to choose delegates from 22 political parties to fill 123 seats in the National Assembly.

Counting of the ballots is expected to being on Monday.

The Cambodian People's Party (CPP) is favoured to win the contest over FUNCINPEC while the long-shot Sam Rainsy Party is expected to pick-up third place.

Cambodian elections usually record a high voter turnout of around 90 percent.