An Afghan soldier has shot and wounded two U.S. troops in northern Afghanistan.

The shooting Monday comes a day after a man dressed in an Afghan police uniform killed three foreign civilian police training advisers working for NATO in western Herat province.

The alliance gave no additional information about the victims in either incident.

Separately, at least five NATO soldiers were killed in roadside bombings in Afghanistan during the weekend.

Roadside bombings are a favorite weapon of Taliban insurgents, hardline Islamists who are waging a campaign to oust the government of President Hamid Karzai and take power.