"Monsters: in just 48 hrs you've raised a quarter of a million dollars for Japan Relief," Gaga said Wednesday on Twitter.

On the same day that Gaga launched her wristwear, rock band Linkin Park began taking orders on its website for T-shirts to raise money for Japan, where 13,000 people are dead or missing after a 9.0-magnitude quake and tsunami.

Both the shirts were designed by band member Mike Shinoda, whose father is Japanese-American. One featured an origami butterfly against a black background and the other has the words "Not Alone," the name of a song by Linkin Park.

The T-shirts cost $25 each and 100 percent of proceeds from sales will be donated to Music for Relief, a group of artists, industry professionals and music fans that works to support disaster relief, Shinoda said on Twitter.

Shinoda tweeted that he is also working on a single to raise money for Japan.

Popstar Katy Perry joined several celebrities who have tweeted to their followers to either pray, shop or donate money for relief efforts in Japan.

Perry tweeted to fans in Germany ahead of a concert there on Tuesday, urging them to buy a light-up wand at the show's merchandise stand.

"All proceeds will go to #Japanredcross. And when I play Firework, let's ignite the light for them tonight," she wrote.

Canadian teen idol Justin Bieber tweeted within hours of the quake on Friday: "Japan is one of my favorite places on earth...it's an incredible culture with amazing people. My prayers go out to them. We all need to help."

The television and cinema worlds are also mobilizing for Japan, with Warner Brothers pledging part of proceeds of DVD sales of its movie "Hereafter" to relief funds for Japan, the Los Angeles Times reported.

The movie starring Matt Damon and Cecile de France was pulled from cinemas in Japan after Friday's quake because it opens with scenes of death and devastation caused by a tsunami.

Other movies have also been deemed inappropriate for screening in Japan in the wake of the disaster that has hit the country, including one called "Aftershock," directed by Xiaogang Feng and originally due to be released next week.

The movie is about the 7.8-magnitude quake that struck the city of Tangshan, China in 1976, killing a quarter of a million people and reducing most of the city to rubble.

Meanwhile, hip-hop stars the Black Eyed Peas have appended a message to the end of their new music video, urging fans to donate to the Red Cross to help victims of the catastrophe in Japan, according to US media reports.

The video for the Black Eyed Peas' song "Just Can't Get Enough" was shot in Japan a week before Friday's massive quake.

"Our heart goes out to all of the Japanese people who have been affected by this natural disaster," Black Eyed Peas' Fergie was quoted as telling the Entertainment Tonight television show, which will air the new video on Thursday.

Celebrities have the potential to raise millions to help the victims of the quake and tsunami in Japan by harnessing their fan bases.

If every one of Lady Gaga's eight million-plus Twitter followers were to buy one of her wristbands and if every Linkin Park follower bought one of Shinoda's T-shirts, $47 million would be raised for Japan.