No, they are agnostic theists, which means that they believe there is no way to know if god exists or not, but they believe in god anyway.

Agnosticism is about believing whether the existence of god is testable, not about whether god actually exists or not.

Obviously the vast majority of agnostics are also atheists, because it’s silly to believe in something for which there is no evidence. But there are some few who feel that god is out there even if we cannot know for sure.