Do research laboratories hire international students with a Bachelor's Degree?
I am not sure you can call it a job, but if somehow you put it nicely as a internship, or unpaid internship, you might be lucky enough to find someone that would like to invest some time on you.

Keep in mind that apart from your will, there must be some supervisor that would be willing to guide you along the process. For that to happen, either there must a be an open position, or you have to convince them that you are worth it.

One thing you could do is not to as for income, since you mention your main goal is to upgrade research experience. If you need income at any case, then you can as for student-job positions which are common in Europe (especially in Germany). But, still the Professor will need to spend some of his funds on you.

Prepare a good motivation letter to convince the Professor, get quality recommendation letters, show some proof that you have the potential to conduct research "independently" (if you have some publications in the field that would help you), make sure you find a research group that fits you (more precisely you fit them, in the sense that you know the field they are working on, you know the tools they use for the specific research)

But since you are a Bachelor student, and I assume you don't have much to offer you should keep your demands as low as possible. Alternately, check if your university has cooperation with other universities, maybe you can go to a university that could fit you as an exchange student?!