Walt Disney Japan raked up a major controversy in the country, after its corporate Twitter account wished readers "congratulations on a no special day" on the 70th anniversary of the US atomic bombing of Nagasaki.

The American entertainment company, following a massive social media uproar, has apologised for the mistake. According to The Associated Press, Walt Disney said on Monday it was deeply sorry and promised to take measures to avoid such mistakes in the future.

The controversy broke on Sunday out after Walt Disney Japan sent out a tweet "A very merry unbirthday to you!" which is from a song in the Disney film "Alice in Wonderland." The message was also accompanied by a picture of Alice from the Disney film.

In Japanese, the phrase tweeted by Disney "Nandemo nai hi Omedeto," means "congratulations for a no special day," Japan Times reported.

Every year on 9 August , 1945, three days after the first atomic bomb was dropped on Hiroshima, Japan holds solemn ceremonies to mourn for the 74,000 people killed in the bombing of Hiroshima-Nagasaki.