Warning by GOV.UK
Disagreements arising from Nepal’s new constitution have led to protests, rallies and strikes occurring frequently throughout Nepal. Monitor the local media and follow the advice of the local authorities and your tour operator. British government officials in Nepal may sometimes defer travel on official business, depending on the security situation at the time. Transport and public services may be disrupted at short notice.
A nationwide general strike is planned for Thursday 9 June 2016 across Nepal. Protests can occur at short notice and turn violent. Clashes between protesters and police may occur anywhere. Stay away from protest areas.
https://www.gov.uk/foreign-travel-advice/nepal