The Russian Foreign Ministry has summoned the American ambassador to protest what it says was the use of U.S.-made advanced missiles in a Ukrainian attack on Russian-annexed Crimea that reportedly killed four people and wounded more than 150.

U.S. officials say Ukraine for the first time has begun using long-range ballistic missiles, striking a Russian military airfield in Crimea and Russian troops in another occupied area overnight.

Boeing's astronaut taxi has returned to Earth from the International Space Station, completing a repeat test flight with a mannequin on board.