(Hillary Clinton and Donald Trump.Brennan Linsley and Chris Carlson for AP Photo)

Hillary Clinton and Donald Trump issued statements on Friday about the shooting rampage that killed at least nine people in Munich, Germany.

"Monitoring the horrific situation in Munich," Clinton tweeted. "We stand with our friends in Germany as they work to bring those responsible to justice."

Clinton named Virginia Sen. Tim Kaine as her running mate on Friday night. She was expected to reveal her pick in a text message to supporters earlier in the day, but the attack may have delayed her announcement, according to The Washington Post.

Trump, who formally accepted the Republican presidential nomination on Thursday, also issued a short statement.

"Our prayers are with all those affected by the horrible attacks in Munich," Trump said. "This cannot continue. The rise of terrorism threatens the way of life for all civilized people, and we must do everything in our power to keep it from our shores."

Investigators said that the suspect's motive was unclear, although German officials initially said that they were treating the attack as an act of terrorism.

The statement echoed Trump's acceptance speech at the Republican National Convention on Thursday, during which he vowed to work with allies of the US to destroy "radical Islamic terrorism." But it was a markedly subdued reaction compared to those he's made after other deadly attacks.

Later, Trump tweeted:

The White House denounced what it called a "heinous act" in a statement from press secretary Josh Earnest:

"The United States condemns in the strongest terms the apparent terrorist attack that has claimed innocent lives in Munich, Germany. We still do not know all of the facts, but we do know that this heinous act has killed and injured multiple individuals in the heart of one of Europe's most vibrant cities. Our thoughts and prayers are with the families and loved ones of the deceased, just as we wish those wounded a full recovery.

"In the midst of this tragedy, the United States will work closely with our German partners to whom we will make available any resources that would assist their investigation, as the President pledged. The resolve of Germany, the United States, and the broader international community will remain unshaken in the face of acts of despicable violence such as this."

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