(CNN) -- Two of the four people killed in a fireworks explosion in Vietnam were German citizens, the German Foreign Office confirmed Thursday.
The explosion, in the Vietnamese capital of Hanoi, also injured three people Wednesday morning, state media reported.
The blast happened when a shipment of fireworks blew up near My Dinh National Stadium, one of 29 sites in the capital where pyrotechnic displays were planned for Hanoi's 1,000th anniversary, the official Viet Nam News reported.
The explosion was blamed on "carelessness" during the transport of two containers of fireworks, the newspaper said.
