I guess the way of doing this will be to remove the data-toggle attribute and have a custom handler for the links.
Something in the lines of:
$("a[data-target=#myModal]").click(function(ev) {
ev.preventDefault();
var target = $(this).attr("href");
// load the url and show modal on success
$("#myModal .modal-body").load(target, function() {
$("#myModal").modal("show");
});
});