London's 'Boxing Day' Shopping Frenzy Rivals 'Black Friday' In The US [PHOTOS]

Today is one of the biggest shopping days of the year in the U.K., with retailers offering blowout sales similar to those offered on Black Friday in the U.S.

The holiday is called "Boxing Day" and it's usually held on Dec. 26, the day after Christmas.

The sales draw huge, chaotic crowds of bargain-hunters every year.

Here's a photo of Oxford Street, one of Europe's busiest shopping streets, early Thursday:

At high-end department store Selfridges in London, shoppers began camping out as early as 11:30 p.m. Christmas Day, according to the Mirror.

As many as 3,500 customers were lined up outside the department store before the doors opened Thursday morning, a spokeswoman for Selfridges told the Mirror.

Analysts expect about $3.4 billion in sales on Boxing Day, including about $739 million in online sales, according to the Guardian.

By comparison, U.S. shoppers spent $9.7 billion on Black Friday, according to research firm ShopperTrak.

Shoppers who queued up outside Harrods were served hot chocolate, smoked salmon canapes and blankets, courtesy of the retailer.

A string quartet also serenaded the shoppers as they waited.

More than 118 million people are expected to visit stores in the U.K. on Boxing Day, according to the Mirror.