Bot are creating new accounts . Any extension to stop them

Yes there are.

This one asks questions before anyone signs up like "What is the name of this planet?" in order to stop bots.
punbb.informer.com/forums/topic/22579/punstopbots/

This one checks known spammers ip's and emails and blocks them.
punbb.informer.com/forums/topic/23957/fancy-stop-spam/

Punstopsbost is not compatible with the latest version
There should be at least  a default captcha; otherwise the forum is an open door to all kind of spam

User URL and all other URLs also should be hiddable by the admin till the user becomes trusted
Spammers should be removed at once instead of one by one delete

Anyway, I disabled  user reg till there  is  solution.

Cheers

Thanks dimkalinux . good fix for bot registration.

There is one problem with registration, though. When I disabled registration, bot were still able to create accounts!

Nice one

I think fancy stop spam is intelligent enough to stop spam posts and creating spam accounts. Additionally you should turn off your guest posting feature.

I use FancyStopSpam on my forums. And in case there still are unwanted registrations, I gave only minimum rights to the basic status of new members, and I upgrade manually, one at a time, the real persons to a member category that I created where they are at last entitled to use normally the forum.