Justin Bieber was allowed into the U.S. after officials at the Los Angeles International Airport detained him for five hours on Thursday (24Apr14).

The troubled pop star's Singapore Airlines flight from Tokyo, Japan arrived at Lax at just after 1pm local time, but Bieber's bodyguards were still waiting for the 20 year old to pass through customs at 4pm.

Around 6.20pm, the Canadian singer was finally released and allowed to leave. He was flanked by four members of his security team as he climbed into a waiting vehicle and was driven away.

It is not confirmed why Bieber was kept at the airport, but a source tells Us Weekly, "It was a routine secondary set of questioning that Justin has to go through now every time he comes back in the country because he's a foreign national."

He later took to Twitter.com to assure his fans he is doing well after the hold-up, writing, "Life is good. Keep it positive always."