Help with one sentence

Hello

イスラムの過激な組織と考えられているグループは、日本人やアメリカ人、イギリス人、フランス人な ど４１人の外国人を人質にしたと言っています。

The part I am having trouble with is the first part of the sentence, the part before the first comma. My thoughts:
Islamic(don't know how to say イスラム in english...) extremist organisations and ... I guess the と is an "and" here and not quotation as there is not a verb or copula before the particle. But if it is an "and" it would "and group(s)" with is being modified by 考えられている which would be passive(or potential?)? . Whether it is passive or potential I can't understand what is being thought?
I just can't make sense of that part. The second part I get.

Could someone perhaps explain it to me?

If context is needed I can provide a link to the article.

How about this?;-)

イスラムの過激な組織だと考えられている

The と is not "and".

It functions the same way as the と in と言う.

Toritoribe said:

How about this?;-)

イスラムの過激な組織だと考えられている

Click to expand...

That I would sort of translate into something like, the islamic group which is thought to be an extremist organisation. But is it the same with and with out the だ???

---------- Post added at 09:00 ---------- Previous post was at 08:55 ----------

Mike Cash said:

The と is not "and".

It functions the same way as the と in と言う.

Click to expand...

Ok. Hmm, how should I phrase this. That と言う you refer to is that as in "say" or like the という that is used for various things like making sentences into nouns or like describing things and so on.
It feels like my explanation was bad...

It's more likely "a group which is thought to be an Islamic extremist organization".

Strictly speaking, it should be だと考えられている, but だ is quite often omitted.

いう in という doesn't mean "to say" in that case.

Oh. That's interesting.

Thank you both for your help.