I know several people who work there and you need to know someone personally who work in the same company that you are planning to apply.
Familiarize the place that you are going to stay while you are abroad. Read the latest news of the country and other negative publications and then decide for yourself if that's the place you want to be in.
Investigate the company that you are working with and if they really have a job for you when you get there and also who are these people around you when you arrived in Yemen?
Researching and more readings will help you answer your own question whether it is safe or not. Good luck!