Letting go of multiple/repeated br tags

Letting go of multiple/repeated br tags

I want to remove multiple <br> tags which are repeated more than 2times,
for example:
This is text blah blah...
<br><br><br><br><br><br>Another text here
Should be:
This is text blah blah...
<br><br>Another text here
I have this:
$str = preg_replace('#(<br\s?/?>)+#', '<br><br>', $str );
But this also replace simple <br> tags with 2 brs, how I could change the
regular expression for this?
Thanks