UNITED NATIONS — Seven U.N. peacekeepers were killed in an ambush Friday in a remote area of southwestern Ivory Coast while trying to protect civilians threatened by attack, the United Nations said.

Bert Koenders, the U.N. envoy to the west African nation, said the peacekeepers were part of a patrol south of Tai in an area which the U.N. mission recently reinforced because of threats of attacks against the civilian population.

He condemned the attack "in the strongest terms" and said the seven peacekeepers who died were from Niger.

Kieran Dwyer, the spokesman for the U.N. peacekeeping department, said "we are moving in reinforcements as soon as we have daylight."

A U.N. official, speaking on condition of anonymity because they were not authorized to speak publicly, said the peacekeeping patrol was attacked by a large number of people. The official estimated that perhaps 40 peacekeepers had been in the area and were dug in overnight to protect the village against a new attack.

Koenders said in the statement that the U.N. mission "will take all necessary measures following this grave violation of international law."

The United Nations has had a peacekeeping mission in Ivory Coast since 2004.

At the end of April, the U.N. said there were about 9,400 peacekeeping troops, 200 military observers and 1,350 international police in the mission along with civilian staff. Over 40 countries are contributing military personnel.