All three appeared to be short-range missiles, rather than the long-range types created to be able to strike the United States, and were launched from Kittaeryong on North Korea's east coast.
Two of the missiles failed in flight and the third blew up "almost immediately", said a spokesman for US Pacific Command.
This led to a dramatic escalation in rhetoric from both Pyongyang and Washington, with US President Donald Trump threatening unleash "fire and fury" on North Korea if it continued making threats against the United States.
The missiles were launched from Kittaeryong, in North Korea's eastern Kangwon province.
The test came just days after senior US officials praised North Korea and leader Kim Jong Un for showing restraint in not firing any missiles since late July.
The presidential office in Seoul said the US and South Korean militaries will proceed with their war games "even more thoroughly" in response to the launch. David Benham said in an emailed statement.
Japan's Chief Cabinet Secretary Yoshihide Suga said the missiles did not reach its territory or exclusive economic zone and did not pose a threat to Japan's safety.
Google and Walmart team up to take on a common enemy: Amazon
This means that voice shopping will enable users to build baskets of everyday products which were purchased earlier. Such a customer connection will provide Google and Walmart insight on shopping activity for future predictions.
The United States and South Korea are technically still at war with the North because their 1950-53 conflict ended in a truce, not a peace treaty.
North Korean state-run media said the country's military could strike the U.S. at any time and that neither Guam, Hawaii nor the USA mainland could avoid the "merciless strike".
"The reality vividly shows that the U.S. ambition for stifling the DPRK [Democratic People's Republic of Korea] remains unchanged no matter how much water may flow under the bridge and the puppet group's ambition for invading the north remains unchanged", North Korea's official news agency KCNA said on Friday.
North Korea's state media also last week reported that leader Kim Jong Un visited the Chemical Material Institute of the Academy of Defence Sciences and inspected designs for two new long-range missiles, raising the threat of a chemical attack as well.
Meanwhile, Japan says it will impose additional sanctions on North Korea.
And then two more were fired within the next half an hour.
Earlier this month, President Donald Trump issued an extraordinary ultimatum to North Korea, warning Pyongyang not to make any more threats against the USA or it will "face fire and fury like the world has never seen".