The assault, which killed an Afghan girl caught in the crossfire, comes as foreigners have been increasingly targeted in the Afghan capital as part of an overall surge in violence ahead of April 5 elections.
Authorities offered conflicting information as they worked to secure the area, but all agreed the violence started when a suicide bomber blew himself up in front of the gate of a guesthouse being used by the California-based Roots of Peace group.
Roots of Peace issued a statement saying the attack started about 6 pm and focused on its residence and a nearby day care center in the Kart-e-Char neighborhood, an affluent area in western Kabul located near the parliament.
It said there apparently were casualties at the day care center, and that five attackers and one child have been confirmed killed, although it did provide more details. It said two Afghan security guards and one foreigner also were wounded.
The US Embassy in Kabul said in a tweet that the group was supported by the US Agency for International Development. It condemned the attack "on an organization that only seeks to help Afghans improve their lives and livelihood."