Katy Perry holds on to US No. 1

Katy Perry has remained at the top spot on the Billboard Hot 100 for a second week with 'California Gurls'.

The song, which also features Snoop Dogg, saw off competition from Usher's 'OMG', which stays in second place.

Elsewhere in the top ten, Lady GaGa's 'Alejandro' reaches a new peak of number six, climbing a place from last week. Drake also enters the top ten at ten from 13 with 'Find Your Love'.

Further down the chart, Justin Bieber's new single 'Never Say Never' debuts at 33, while Shakira's 'Waka Waka (This Time For Africa)' lands at 44.

Christina Aguilera's 'Bionic' charts at 66 and Ne-Yo's new single 'Beautiful Monster' enters at 67. VV Brown's 'Shark In The Water' climbs for a second week, from 97 to 83.

The top ten singles in full (click where possible for our reviews):

1. (1) Katy Perry: 'California Gurls'
2. (2) Usher: 'OMG'
3. (3) B.o.B ft. Eminem & Haley Williams: 'Airplanes'
4. (5) Billionaire: Billionaire
5. (4) Ke$ha: 'Your Love Is My Drug'
6. (7) Lady GaGa: 'Alejandro'
7. (6)Taio Cruz ft. Ludacris: 'Break Your Heart' (5) B.o.B ft. Bruno Mars: 'Nothin' On You'
8. (11) Eminem: 'Not Afraid'
9. (9) Black Eyed Peas: Rock That Body
10. (13) Drake: Find Your Love