$ composer require evheniy/sitemap-xml-bundle "1.*"

"evheniy/sitemap-xml-bundle": "1.*"

public function registerBundles()
    {
        $bundles = array(
            ...
            new Evheniy\SitemapXmlBundle\SitemapXmlBundle(),
            new AppBundle\AppBundle(),
            ...
        );
        ...
...

<?php

namespace AppBundle\Command;

use Evheniy\SitemapXmlBundle\Command\SiteMapDumpCommand as Command;

class SiteMapDumpCommand extends Command
{
    protected function setEntities()
    {
        $this->siteMapEntity = $this->serviceManager->createSiteMapEntity();
        $this->dumpEntity->setDomain('site.com');
        foreach ($pages as $page) {
            $this->siteMapEntity
                ->addLocation(
                    $this->serviceManager->createLocationEntity()
                        ->setLocation($page['url'])
                        ->setLastmod(new \DateTime($page['date']))
                );
        }
    }
}

<?php

namespace AppBundle\Command;

use Evheniy\SitemapXmlBundle\Command\SiteMapDumpCommand as Command;

class SiteMapDumpCommand extends Command
{
    protected function setEntities()
    {
        $this->siteMapIndexEntity = $this->serviceManager->createSiteMapIndexEntity();
        $this->dumpEntity->setDomain('site.com');
        $siteMapEntity = $this->serviceManager->createSiteMapEntity();
        foreach ($pages as $page) {
            $siteMapEntity->addLocation(
                $this->serviceManager->createLocationEntity()
                    ->setLocation($page['url'])
                    ->setLastmod(new \DateTime($page['date']))
            );
        }
        $this->siteMapIndexEntity->addSiteMap($siteMapEntity);
    }
}

app/console sitemap:dump

$this->siteMapIndexEntity
    ->addSiteMap(
        $this->serviceManager->createSiteMapEntity()
            ->addLocation(
                $this->serviceManager->createLocationEntity()
                    ->setLocation('http://site.com/page1.html')
                    ->setLastmod(new \DateTime())
            )
            ->addLocation(
                $this->serviceManager->createLocationEntity()
                    ->setLocation('http://site.com/page2.html')
                    ->setLastmod(new \DateTime())
                    ->addImage(
                        $this->serviceManager->createImageEntity()
                            ->setLocation('http://site.com/logo.png')
                            ->setTitle('Logo')
                    )
            )
    );