aşağıdaki kodların çıktısı:

http://img1.cihan.com.tr/d.jpg
http://img1.cihan.com.tr/g51222.jpg
http://img1.cihan.com.tr/224.jpg
http://img1.cihan.com.tr/.jpg

Kodlar:

<?php
$xml = @simplexml_load_string('<rss version="2.0"
xmlns:media="http://search.yahoo.com/mrss/"
xmlns:dc="http://purl.org/dc/elements/1.1/">

<channel>	
<title>cihan haber :: GÜNCEL</title>
<link>http://www.cihan.com.tr/</link>
<description>Cihan Haber Ajans</description>
<item>
	<title>istanbulda Zabıtası’ndan Sarıkız operasyonu</title>
	<link>http://www.cihan.com.tr/nNy8x</link>
	<description>istanbulda................... CİHAN</description>
	<category>GÜNCEL</category>
	<pubDate>Mon, 29 Apr 2013 07:32:55 GMT</pubDate>
	<guid>http://www.cihan.com.tr/news/1019517x</guid>
	<dc:creator>CİHAN</dc:creator><dc:date>2013-04-29T07:32:55Z</dc:date>
	<media:content type="image" url="http://img1.cihan.com.tr/d.jpg">
		<media:copyright>CIHAN HABER</media:copyright>
		<media:keywords>2304163</media:keywords>
		<media:title>istanbu syonu.</media:title>
	</media:content>
 	<media:content type="image" url="http://img1.cihan.com.tr/g51222.jpg"> 
		<media:copyright>CIHAN HABER</media:copyright>
		<media:keywords>2304163_1</media:keywords>
		<media:title> an bayıltıcı andı.</media:title>
	</media:content>
	<media:content type="image" url="http://img1.cihan.com.tr/224.jpg">
		<media:copyright>CIHAN HABER</media:copyright>
		<media:keywords>2304163_2</media:keywords>
		<media:title> ka yle yakalandı.</media:title>
	</media:content>
	<media:content type="image" url="http://img1.cihan.com.tr/.jpg">
		<media:copyright>CIHAN HABER</media:copyright>
		<media:keywords>2304163_3</media:keywords>
		<media:title>  1 saat s ndı.</media:title>
	</media:content>
	<media:content type="image" url="http://img1.cihan.com.tr/d25.jpg">
		<media:copyright>CIHAN HABER</media:copyright>
		<media:keywords>2304163_4</media:keywords>
		<media:title>  yakalandı.</media:title>
	</media:content>
	</item>
</channel>
</rss>');

foreach($xml->channel->item as $news)
{
	$resimler = $news->children('http://search.yahoo.com/mrss/');
	$say = $resimler->count()-1;
	for($i=0;$i<$say;$i++){	
		echo $resimler[$i]->attributes()['url'].'<br />';
	}
}

Bakınız : SimpleXMLElement::children
Bakınız : SimpleXMLElement::attributes
Bakınız : SimpleXMLElement::count

http://www.php.net/manual/en/class.simplexmlelement.php