Laravel 5.6 - 404 though route defined

Trying to access admin/users/multidel and its giving me a 404 error

Chrome console.log:

DELETE http://****.test/admin/users/multidel 404 (Not Found)

web.php

Route::group(['middleware'=>'admin'], function(){
    Route::get('/admin', 'AdminController@index')->name('admin.home');;

    Route::delete('admin/users/multidel', 'AdminUsersController@multiDel')->name('users.multidel');
    Route::resource('admin/users', 'AdminUsersController');
});

php artisan route:list

+--------+-----------+-------------------------+------------------+------------------------------------------------------------------------+--------------+
| Domain | Method    | URI                     | Name             | Action                                                                 | Middleware   |
+--------+-----------+-------------------------+------------------+------------------------------------------------------------------------+--------------+
|        | GET|HEAD  | /                       |                  | App\Http\Controllers\HomeController@index                              | web,auth     |
|        | GET|HEAD  | admin                   | admin.home       | App\Http\Controllers\AdminController@index                             | web,admin    |
|        | POST      | admin/users             | users.store      | App\Http\Controllers\AdminUsersController@store                        | web,admin    |
|        | GET|HEAD  | admin/users             | users.index      | App\Http\Controllers\AdminUsersController@index                        | web,admin    |
|        | GET|HEAD  | admin/users/create      | users.create     | App\Http\Controllers\AdminUsersController@create                       | web,admin    |
|        | DELETE    | admin/users/multidel    | users.multidel   | App\Http\Controllers\AdminUsersController@multiDel                     | web,admin    |
|        | PUT|PATCH | admin/users/{user}      | users.update     | App\Http\Controllers\AdminUsersController@update                       | web,admin    |
|        | GET|HEAD  | admin/users/{user}      | users.show       | App\Http\Controllers\AdminUsersController@show                         | web,admin    |
|        | DELETE    | admin/users/{user}      | users.destroy    | App\Http\Controllers\AdminUsersController@destroy                      | web,admin    |
|        | GET|HEAD  | admin/users/{user}/edit | users.edit       | App\Http\Controllers\AdminUsersController@edit                         | web,admin    |
|        | GET|HEAD  | api/user                |                  | Closure                                                                | api,auth:api |
|        | GET|HEAD  | home                    | home             | App\Http\Controllers\HomeController@index                              | web,auth     |
|        | GET|HEAD  | login                   | login            | App\Http\Controllers\Auth\LoginController@showLoginForm                | web,guest    |
|        | POST      | login                   |                  | App\Http\Controllers\Auth\LoginController@login                        | web,guest    |
|        | POST      | logout                  | logout           | App\Http\Controllers\Auth\LoginController@logout                       | web          |
|        | POST      | password/email          | password.email   | App\Http\Controllers\Auth\ForgotPasswordController@sendResetLinkEmail  | web,guest    |
|        | POST      | password/reset          |                  | App\Http\Controllers\Auth\ResetPasswordController@reset                | web,guest    |
|        | GET|HEAD  | password/reset          | password.request | App\Http\Controllers\Auth\ForgotPasswordController@showLinkRequestForm | web,guest    |
|        | GET|HEAD  | password/reset/{token}  | password.reset   | App\Http\Controllers\Auth\ResetPasswordController@showResetForm        | web,guest    |
|        | POST      | register                |                  | App\Http\Controllers\Auth\RegisterController@register                  | web,guest    |
|        | GET|HEAD  | register                | register         | App\Http\Controllers\Auth\RegisterController@showRegistrationForm      | web,guest    |
+--------+-----------+-------------------------+------------------+------------------------------------------------------------------------+--------------+

I've defined it in web.php, and its above the resource (users) so should take precedence over any other route in the 'user' resource. What am I missing?

via Chebli Mohamed