连续跳过foreach循环中的元素

I'm trying to create a foreach loop which will iterate over groups of six elements and skip the first element each time. For example:

1
2
3
4
5
6
7
8
9
10
11
12

I would want to pull out all numbers other than 1 and 6. So far I have it working by pulling out #1 but then the loop dies. Here is my code so far:

$counter = 0;
  $items = $xml->channel->item;
  foreach ($items as $item) {
    if ($counter ++ < 5)  { //Skip item 1
      echo $item->link . "<br />";
      $counter = 0;
      continue;
  }
}

Any help appreciated, thanks!

Something like this?

$counter = 0;
$items = $xml->channel->item;
foreach ($items as $item) {
    $counter++;
    if ($counter % 5 == 1)  { continue; }
    echo $item->link . "<br />";
}