Peace Brigades International also uses tactics of accompanying people at risk, positioning themselves in front of soldiers, and witnessing violence.
PBI volunteers come from United States, many European countries, Australia, Japan, and many other countries. They must be strongly committed to non-violence, and fluent in local languages.
PBI was founded in 1981 and has had projects in the Balkans, El Salvador, Sri Lanka, Haiti, Canada, and the USA. They have current projects in Colombia, Guatemala, Indonesia, Nepal, and Mexico.
See a good Wikipedia article.