Angular2 Observable, interating through object in service gives errors

I've looked on the board and on many sites but can't find a solution to my issue.

The issue has already been discussed but nothing seems to work on my code. So! First, the JSON produced by my middleware is like so:

{
  "uuid": "5c5260ec-5bcd-451a-ad68-57eb9572c185",
  "latitude": 41,
  "longitude": 1,
  "temoin": {
    "numeroDeTelephone": 342391,
    "nom": "bruce",
    "prenom": "wayne",
    "sexe": "m",
    "age": 12,
    "taille": 150,
    "poids": 62,
    "groupeSanguin": "a+"
  }
}

As you can see, I have two objects (which are described in my Angular app) the main object is signalement which contains a temoin object.

Signalement:

import { TemoinObjet } from './temoin.objet';

export class Signalement{
    public uuid: String;
    public latitude: any;
    public longitude: any;
    public temoin: TemoinObjet;    
}

Temoin:

export class TemoinObjet{
    public telephone: Number;
    public prenom: String;
    public nom: String;
    public sexe: String;
    public age: Number;
    public taille: Number;
    public poids: Number;
    public groupeSanguin: String;
}

I switched from promises in the component to a service intended to get data:

import { Http, Response } from '@angular/http';
import { Injectable } from '@angular/core';

import { Observable } from 'rxjs/Rx';
import 'rxjs/add/operator/toPromise';
import 'rxjs/add/operator/map';

import { Signalement } from '../domain/objets/signalement.objet';
import { TemoinObjet } from '../domain/objets/temoin.objet';

@Injectable()
export class SignalementService{  
    private urlRef: string = 'http://localhost:8080/Asklepios-1.0/ws/signalement';

    constructor(private http: Http) {
    }

    recupererSignalements():Observable<Signalement[]>{
        return this.http.get(this.urlRef).map((res:Response) => res.json());
    }

    get(uuidARetrouver: String, liste:any) : Signalement{
         return liste.find(s => s.uuid === uuidARetrouver);
    }
}

I'm using the recupererSignalements() method which returns an Observable.

In my component I've created a method with the same name and called it in the ngOnInit. Here's the full component:

    import { Component, OnInit } from '@angular/core';
import { Signalement } from './domain/objets/signalement.objet';
import { SignalementService } from './services/signalement.service';
import { TemoinObjet } from './domain/objets/temoin.objet';
import { Observable } from 'rxjs/Rx';

@Component({
    selector: 'liste-signalement',
    templateUrl: './list_signalement.html',
    providers: [SignalementService]

})

export class ListSignalementsComponent implements OnInit {
    signalements: Signalement[];

    constructor(private signalementService: SignalementService){
    }

        ngOnInit(){
            this.recupererSignalements();
            console.log(this.signalements);
           }

           recupererSignalements(){
               this.signalementService.recupererSignalements().subscribe(donnees => this.signalements = donnees, ()=>console.log("Fail"), ()=>console.log("Done : "+this.signalements));
           }
}

Once it's done I want to iterate over the signalements array to show the information in my view, but everytime I get the error Error: Error trying to diff '[object Object]' at DefaultIterableDiffer.diff. When using *ngFor I instead see:

Error: Cannot find a differ supporting object '[object Object]' of type
'object'. NgFor only supports binding to Iterables such as Arrays. at 
NgForOf.ngOnChanges.

Here's the view :

<ul>
    <li *ngFor="let signalement of signalements">
        {{signalement.uuid}}
    </li>
</ul>

I've tried the asyncpipe. Using this I get no more errors but can't see anything in my view.