Ethiopia says the United States will send FBI investigators to look into Saturday's deadly attack on a massive rally for the new prime minister.

Foreign Ministry spokesman Meles Alam tells The Associated Press that Under Secretary of Commerce Gilbert Kaplan made the remark after meeting with the foreign minister in the capital, Addis Ababa.

Witnesses said a man in police uniform tried to hurl a grenade at the stage after Prime Minister Abiy Ahmed addressed a crowd of tens of thousands cheering a wave of reforms in the East African country.

Two people have died and more than 150 were hurt. More than 30 people have been arrested.

The ruling party, just weeks ago the target of widespread anti-government protests, blamed "desperate anti-peace elements" and vows to continue the reforms.