react-router – pass props to handler component

I have the following structure for my React.js application using React Router:

var Dashboard = require('./Dashboard');
var Comments = require('./Comments');

var Index = React.createClass({
  render: function () {
    return (
        <div>
            <header>Some header</header>
            <RouteHandler />
        </div>
    );
  }
});

var routes = (
  <Route path="https://stackoverflow.com/" handler={Index}>
    <Route path="comments" handler={Comments}/>
    <DefaultRoute handler={Dashboard}/>
  </Route>
);

ReactRouter.run(routes, function (Handler) {
  React.render(<Handler/>, document.body);
});

I want to pass some properties into the Comments component.

(normally I’d do this like <Comments myprop="value" />)

What’s the easiest and right way to do so with React Router?