Tonight on

P. B.

PBS News Weekend, Terror in Moscow, the deadliest massacre in decades leaves Russia on edge just days after

president Vladimir Putin was reelected.

They were just walking and shooting as they went along. There were five or six

of them. They were just walking and

gunning down everyone methodically in silence. Then the working conditions

were migrant farm workers and their role they play in U.S. economic growth and how the residents of a small

Wisconsin town are dealing with a surge in migrants. Good evening I'm John Yang. Russian President Vladimir Putin has vowed to punish those responsible for the terror attack on a suburban Moscow concert hall that killed at least 133 people and according to Russian officials left about 145 more wounded.

It was one of the worst acts of terror in Russia in decades.

Throughout Russia tonight security has been beefed up and in Moscow

people are remembering the dead and offering help to the wounded.

Hundreds of people lined up in the rain this morning in Moscow to donate blood and plasma

giving what they can for the wounded from last night's carnage.

Of course I was shocked and felt fear and horror. carnage.

Of course I was shocked and felt fear and horror.

I've been to a concert at Crocus myself and when I saw those horrible videos, I was shocked

and in tears even now when I speak about it. It was very scary to see it all.

A branch of the Islamic State based in Afghanistan claimed responsibility for the attack.

It began with

gunman storming the hall, firing point blank at people who had

gathered for a rock concert.

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