Launching Projectile [Game Issue]

[Vinwarez]

Everything works until one bullet reaches the end of the form.

Code:

Public Sub PlayerBullets_Act()
        'This method moves the player bullets and detects their collisions. It should be called every
        'time the timer ticks
        For Each bullet As PictureBox In playerBullets
            If (bullet.Location.Y <= 0) Then
                'The bullet has moved off of the screen, we need to remove it to conserve system resources
                Controls.Remove(bullet)
                playerBullets.Remove(bullet)
            End If

            'TODO: Check for collisions with enemies here

            bullet.Location = New System.Drawing.Point(bullet.Location.X, bullet.Location.Y - 2) 'Move the bullet up
        Next


    End Sub

The problem is at the Next. This is what I get:

Collection was modified; enumeration operation may not execute.