Ionic 2 seems doesn't resolve module correctly

My project has the following folder structure:

        - file1.ts
        - file2.ts
        - file3.ts
        - index.d.ts
        - service1.ts
        - service2.ts
        - service3.ts
        - index.d.ts
    - app.ts

In the three file file1.ts, file2.ts and file3.ts there are 3 classes defined like so:

- file1.ts
  export class File1 {}

- file2.ts
  export class File2 {}

- file3.ts 
  export class File3 {}

The index.d.ts file, inside the support folder, has the following content:

export * from './file1.ts';
export * from './file2.ts';
export * from './file3.ts';

The three file service1.ts, service2.ts and service3.ts, inside the services folder, contain three classes (Service*.ts) defined like the ones in file*.ts files. The file index.d.ts has the same structure of the other described above.

In the file app.ts there are two import statements like these:

import {Service1, Service2, Service3} from './services';
import {File1, File2, File3} from './support';

When I compile the project using ionic build the following two errors are raised:

Error: Cannot find module './services' from 'E:\<project dir>\app'
Error: Cannot find module './pages' from 'E:\<project dir>\app'

The command ionic serve doesn’t work because the app.bundle.js is not generated.

What am I doing wrong?

Renaming the file index.d.ts to index.ts the problem is solved.