An 18-year-old was stabbed to death in front of horrified shoppers Monday during a fight between two groups of youths on London's Oxford Street, one of Europe's busiest retail districts which was packed with thousands of bargain hunters.

Police said they had arrested about 10 people over the fatal attack at 1:45 p.m. British time that led to the closure of parts of the capital's main shopping thoroughfare, popular with Londoners and visitors alike.

The day after Christmas Day is traditionally one of the busiest of the year on Oxford Street, with retailers starting their post-Christmas sales.

Later Monday at about 6:00 p.m. British time a 21-year-old man was stabbed in the leg near Oxford Circus, one of Oxford Street's main junctions. Police said his injuries were not life-threatening and added it was too early to say if the two incidents were linked.

Officers arrested three men in relation to the second stabbing.

(Reporting by Sudip Kar-Gupta; Editing by Matthew Jones)