Tinie Tempah leads the nominations for the 2010 MOBO Awards. The chart-topping U.K. rapper is up for four awards at the ceremony next month.

Dizzee Rascal, Professor Green, N-Dubz and Plan B each have three nominations for the U.K. urban music awards. This year's ceremony takes place at Liverpool Echo Arena on Oct. 20 and it will be televised live on BBC Three.

It marks the 15th year of the MOBOs, which was established to celebrate music of black origin. And the 2010 event comes at a time when U.K. urban acts are enjoying commercial success at home, particularly in the singles chart, and internationally.

"MOBO music is now the U.K. mainstream," said the organizers in a statement. The nominees were unveiled at the May Fair Hotel in London tonight (Sept. 8). They were decided by a music panel of DJs, music editors, journalists, broadcasters and other tastemakers.

Rihanna, Black Eyed Peas, Beyonce, Alicia Keys, Drake and Jason Derulo are nominated in the best international act category. Performers for the ceremony have not yet been confirmed, but N-Dubz hinted at the nominations event tonight that they would be playing at the show next month.

Richard "Fazer" Rawson and Tula "Tulisa" Contostavlos attended the launch, although Dino "Dappy" Contostavlos from the group missed a flight from Greece. Tulisa told the audience that the MOBOs means a lot to them.

"I remember looking at the MOBO Awards and thinking 'oh my god, how would it feel to win one of those?'" she said. "When we finally did [in 2007 for best U.K. newcomer] it was one of the most amazing feelings."

N-Dubz also won the MOBOs for best album ("Uncle B") and best U.K. act last year.

South London rapper Tinie Tempah also attended the nominations launch. He has been one of this year's breakout urban artists in the U.K. and his debut album "Disc-Overy" (Parlophone/EMI) will be released Oct. 4. He is up for best newcomer, best U.K. act, best video and best song (in association with PRSforMusic) for his U.K. No. 1 single "Pass Out."

To celebrate the 15th anniversary, this year's best U.K. Act (in association with main awards sponsor Lebara Mobile), best international act, and best African act will all start off with 15 nominations. These will then be narrowed down to five main nominees in each category.

All of this year's categories will be voted for by the public, with the exception of both best jazz act and best gospel act.

MOBO is also capitalizing on the success of the genre and helping new talent with new activities, including the first ever national MOBO Tour. It will call at six U.K. cities in October and feature Skepta, Aggro Santos, Mz Bratt and Scorcher, who also attend the nominations.

"I am very proud of the level of talent in the U.K.," said Kanya King, CEO and founder of MOBO, in a statement.

2010 MOBO Nominations:

Best Newcomer
Tinie Tempah
Professor Green

Best U.K. Act
Tinie Tempah
Jay Sean
Tinchy Stryder
Taio Cruz
Roll Deep
Dizzee Rascal
Alexandra Burke
Plan B
Leona Lewis

Best Song
Taio Cruz ft Ke$ha - "Dirty Picture"
Tinie Tempah - "Pass Out"
N-Dubz ft Mr Hudson - "Playing With Fire"
Mark Ronson & The Business INTL ft Q-Tip & MNDR - "Bang, Bang, Bang"
Professor Green ft Ed Drewett - "I Need You Tonight"

Best U.K. R&B/Soul
Natalie Williams
Corinne Bailey Rae
Plan B

Best U.K. Hip Hop/Grime
Professor Green

Best International Act
Alicia Keys
Jay Z
Janelle Monae
Black Eyed Peas
Nicki Minaj
Jason Derulo
Lil Wayne
Travie McCoy
Trey Songz

Best Reggae
Damian Marley
Vybz Kartel

Best Album
Plan B - "The Defamation of Strickland Banks" (679/Atlantic)
JLS - "JLS" (Epic)
N-Dubz "Against All Odds" (UMTV)
Chipmunk -"I Am Chipmunk" (Jive/Columbia)
Dizzee Rascal - "Tongue in Cheek" (Dirtee Stank)

Best Video
Mark Ronson & The Business INTL ft Q-Tip & MNDR - "Bang, Bang, Bang"
Tinie Tempah ft Labrinth - "Frisky"
Tinchy Stryder - "You're Not Alone"
Alesha Dixon - "Drummer Boy"
Dizzee Rascal - "Dirtee Disco"

Best African Act
K'Naan (Somalia)
P-Square (Nigeria)
Hip Hop Pantsula (South Africa)
JJC (Nigeria)
Banky W. (Nigeria)
Concha Buika (Equatorial Guinea)
Mulatu Astatke (Ethiopia)
Wanlov the Kubolor (Ghana)
Angélique Kidjo (Benin)
M3NSA (Ghana)
Yuri Da Cunha (Angola)
Tinny (Ghana)
Waldemar Bastos (Zimbabwe)
Staff Benda Bilili (Congo-Kinshasa)
BLK JKS (South Africa)

Best Gospel Act
Faith Child
Guvna B
Rachel Kerr
Jake Isaac
Beverley Trotman

Best Jazz Act
Robert Glasper
Brad Mehldau
John McLaughlin