$query = new EntityFieldQuery();
$query->propertyOrderBy('created', 'DESC');
$query->entityCondition('entity_type', 'node')
    ->entityCondition('bundle', 'news')
    ->propertyCondition('status', 1)
    ->fieldCondition('field_pub_year', 'value', $year, '=');
if(isset($_GET['country_id'])){
    $country = $_GET['country_id'];
    $query->fieldCondition('field_related_country', 'target_id', $country, '=');
}
if(isset($keywords)){
    $query->addTag('search');
}
$result = $query->execute();

function hook_query_search_alter(QueryAlterableInterface $query){
    $or = db_or()
      ->fieldCondition('title', 'value','%'. $keywords .'%', 'LIKE')
      ->fieldCondition('body', 'value','%'. $keywords .'%', 'LIKE');
    $query->condition($or);
}