Open multiple windows/tabs from C# code behind

I'm looking for a way to open multiple browser windows (or tabs) from code behind. Currently the user clicks submit and the code behind uses a Response.Redirect to redirect the user to a confirmation page. I need to add some logic to open n number of tabs (based on the user's input) in addition to the redirect.

I attempted Process.Start(url) but that does not seem to work once the site is deployed to IIS. It's worth mentioning that I do not know the target urls at design time. Here's what I have so far.

public void FormSubmit(object sender, EventArgs e)
{
    ...//Analyze data and populate listOfStringUrls
    foreach (string x in listOfStringUrls)
    {
        Process.Start(x);
    }
    Response.Redirect("/Web/Confirmation.aspx");
}

Any help is appreciated.