How to make the search in Cyrillic and Latin alphabet work?

Question

API

Searching the wall using Cyrillic characters through the VK API wall.search method works, but using the execute+wall.search methods it does not find either Cyrillic characters or Latin characters, but only numeric values. What could be the problem?

$owner_id = '141.....'
$s_query = 'Хабаровск'

$code ="var walls = API.wall.search({ owner_id : $owner_id, count : 5, query: $s_query});
        	return walls;";


$wall_get = VkApi('execute', array(
  'code' => $code,));

foreach ($wall_get['response']['items'] as $value) {
print_r($value['text']); echo'<hr>';