Three of Nepal's top political leaders have promised to end election-related violence before next week's national poll. International election observers have said attacks by Maoists and militants could undermine the April 10 election. Liam Cochrane reports for VOA News from Kathmandu.

Nepal's prime minister, along with the chairman of the former rebel Maoists and the leader of another major political party signed an agreement promising to end violence during their election campaigns.

In recent weeks, there have been daily clashes between political party supporters, with several deaths and many injuries.

Nepal's voters will choose members of a Constituent Assembly that will rewrite the country's constitution. But international observers say intimidation and violence could undermine the credibility of the April 10 election.

The Asian Network for Free Elections has observers in 20 of Nepal's 75 districts. Observer-mission assistant Adam Cooper says they have seen the security situation get worse.

"The election environment is overall deteriorating," he said. "We have seen the level of violence and intimidation go up, even in the short two weeks that our observers have been in the field. Candidates are finding it increasing difficult to campaign freely, voters are increasingly intimidated with threats and violence."

Cooper said the Maoists were the main aggressors, as well as armed groups operating in southern districts.

The observer group and the United Nations have also expressed concern that some of the 31,000 Maoist fighters who are supposed to be staying in U.N.-supervised camps across the country, have left and are joining the campaigning.

Cooper welcomed the fresh promises of peace from the political leaders, but remained skeptical.

"We very much hope that this latest declaration will be more effective, but until our observers in the field report that the level violence is going down we will assume that it is simply rhetoric," said Cooper.

More than 500 international observers and tens of thousands of Nepali observers will monitor the election next week, which is one of the key parts of a peace deal that ended a decade-long civil war in Nepal.