WASHINGTON

The US on Saturday "strongly" condemned Friday's "heinous" terrorist attack in Moscow, as well as "terrorism in all its forms."

"The United States strongly condemns yesterday’s deadly terrorist attack in Moscow," US Secretary of State Antony Blinken said in a statement.

"We send our deepest condolences to the families and loved ones of those killed and all affected by this heinous crime," he said, adding: "We condemn terrorism in all its forms and stand in solidarity with the people of Russia in grieving the loss of life from this horrific event."

At least 133 people were killed and 145 were injured after gunmen opened fire at concertgoers late Friday. The attack took place as the rock band Picnic was about to perform at the Crocus City Hall just west of Moscow.

Russian authorities have arrested 11 people in connection with the attack, including four directly involved, according to the Federal Security Service.