$re = '/a href="([^"]+)".+img src="([^"]+)/m';
$str = '<p style="text-align: center;"><a href="/upload/obzor-PG32UQX/" class="fancybox"><img src="/upload/obzor-PG32UQX/01_tab1.png"></a></p>
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php