Weird. Works for me: 
#!/usr/bin/perl
use warnings;
use strict;
use utf8;

use WWW::Mechanize qw();

my $mech = WWW::Mechanize->new;
$mech->credentials('user' => 'pass');
$mech->get('http://kreml.ru/');

my $content = $mech->text();
$content =~ s/\n\r//g;

binmode STDOUT, ':utf8';
print $1,"\n" if $content =~ /(\bКремл&#
+1100;.*\"\b)(.*)/i;

[download]
The regex looks like this in fact: 
$content =~ /(\bКремль.*\"\b)(.*)/i
لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ

In reply to Re^5: RegEx: Detecting the certain cyrillic words by choroba
in thread RegEx: Detecting the certain cyrillic words by programmer.perl

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