Lady Gaga and Ariana Grande urged US leaders Monday to act to tighten gun laws following the carnage in Las Vegas, as artists voiced shock at the deadliest shooting in modern US history.

While most artists left their comments to general messages of sympathy after the assault on a country music festival, Gaga used her social media power to press politicians.

"This is terrorism plain and simple. Terror bares (sic) no race, gender or religion. Democrats & Republicans please unite now," the pop star wrote to more than 71 million followers on Twitter, where her account is the seventh most popular.

She took to task the call for prayers by House Speaker Paul Ryan, who like President Donald Trump and most other Republican leaders is a staunch opponent of regulations on guns.

"Prayers are important but @SpeakerRyan @realDonaldTrump blood is on the hands of those who have power to legislate. #GunControl act quickly," she wrote.

Gaga also invited fans to join her in a live-streamed 20 minutes of silent meditation or prayer "to connect us all through inner peace."

Grande -- whose own concert in Manchester was attacked in May by a supporter of the Islamic State group, killing 22 people -- indicated that she saw little distinction with the assault in Las Vegas, where the gunman's motivations were not immediately clear.

"My heart is breaking for Las Vegas. We need love, unity, peace, gun control & for people to look at this & call this what it is = terrorism," Grande tweeted.

- Most artists avoid politics -

Country turned pop superstar Taylor Swift, the fourth most followed person on Twitter, steered clear of politics as she wrote: "There are no words to express the helplessness and sorrow my broken heart feels for the victims in Vegas and their families."

Rihanna similarly tweeted: "Saying a prayer for all the victims & their loved ones, also for the residents & visitors of Las Vegas! This was a horrific act of terror!!"

At least 58 people were killed and 500 were injured when a heavily armed gunman opened fire from his hotel room onto an open-air country music festival on the Las Vegas Strip.

Jason Aldean, who was playing the headlining set when bullets began raining down, called the attack "beyond horrific."

"It hurts my heart that this would happen to anyone who was just coming out to enjoy what should have been a fun night," he wrote on Instagram.

Maren Morris, who played the same Route 91 Harvest festival on Saturday, recalled that "we were all singing" the day before the tragedy.

"I'm in shock over this. Heartbroken for all those lives taken too soon," she tweeted.

Source: AFP