Moyes was concerned for family after Hammers win
David Moyes was concerned for members of his family after AZ Alkmaar fans attempted to attack a section of West Ham's support following the Londoners' Europa Conference League semi-final win in the Netherlands.
Pablo Fornals' injury-time winner prompted a gang of black-shirted, hooded AZ ultras to attempt to storm into the area reserved for friends and family behind the dugout.
Players including Michail Antonio, Said Benrahma, Aaron Cresswell and Flynn Downes climbed over the advertising hoardings in a bid to stop the trouble.
Moyes, who's 87-year-old father David Snr was at the match, said: "I can't explain what happened and why it happened.
"I can only say the players were involved because it was the family section and most of their family and friends were in there. That was probably the reason for the reaction.
"Was I worried? Yeah, my family were there and I had friends in that section. You're hoping they would try and get themselves away from it.
"I didn't recognise it because I'd gone onto the pitch. Security wanted to take me inside, but I had to make sure my players weren't involved.
"What we don't want to do is in any way blight the night because it certainly wasn't West Ham supporters looking for trouble. Hopefully they'll look into it."
Hammers goalkeeper Alphonse Areola added: "When families or friends are coming to the stadium we don't want to see things like that.
"They want to enjoy the event and we want to enjoy it with them as well. We were worried about them."
During last week's first leg at the London Stadium, members of AZ players' families were involved in a confrontation with West Ham fans.
AZ boss Pascal Jansen said: "What happened last week was very unfortunate and then you get the same feeling as what happened tonight.
"I feel a little bit ashamed it happened in our stadium but you have to control your emotions."
The incident overshadowed West Ham reaching a first European final in 47 years and moving to within one match of a first trophy since the FA Cup in 1980.