Justin Bieber has apologised for a second time over his recent visit to a controversial war shrine during a visit to Japan.

The troubled star ignited anger among Korean fans when he posed for photos at the Yasukuni Shrine in Tokyo - which apparently pays tribute to war criminals as well as fallen soldiers.

And although he has previously said sorry and attempted to explain that he was misled about the shrine, he has now issued an unqualified apology on Twitter.

He tweeted: "Found out that when i was in Japan I hurt my fans in Korea when visiting that shrine. That was never my intent. I love Korea. Im sorry.

"I would never do anything to hurt my fans. I love all people. my heart goes out to the people of Korea at this time. love you.

"I understand the responsibility of my position. i love all people. keeping it positive. Love to all the #Beliebers around the world. Keep smiling."

found out that when i was in Japan I hurt my fans in Korea when visiting that shrine. That was never my intent. I love Korea. Im sorry

— Justin Bieber (@justinbieber) May 1, 2014

Biebs this week posted a marriage proposal on his Instagram account.