Ikosi said locals heard gunshots, but that the attackers had fled the scene by the time people awoke in the morning.
Heavy MONUC losses
Ban Ki-moon, the UN secretary-general, condemned the attack and called for Congo's government to launch an immediate investigation.
He also sent condolences to the Indian government and the families of the three soldiers, and expressed his support for the UN peacekeeping mission. The UN security council issued a similar statement.
The UN mission in Congo, known as MONUC, has lost more than 100 peacekeepers since 1999.
Congo's president has said that he wants all the peacekeepers out before September 2011. The UN approved a partial withdrawal earlier this year.
John Holmes, the UN humanitarian chief, has warned that violence may spiral out of control if the peacekeepers all leave.
Rebels ousted longtime dictator Mobutu Sese Seko in 1997, then turned on each other in back-to-back civil wars that became an international scramble for the country's minerals and drew in soldiers from more than a half-dozen African nations.
The $1.35 billion-a-year UN mission helped hold DR Congo's first democratic elections in 40 years in 2006, although results were disputed and critics said the process favored the incumbent, Joseph Kabila.