Yes, even a small injury to urethra (penis tube from which urine and semen is passed) and prostate can cause blood in urine. The other common cause of blood in semen is prostatitis (infection in prostate). Most of the time this heals spontaneously and stops on its own and no treatment is required. But if it is persistent; you may need a course of antibiotics. Please read this resource;
Please feel free for your follow up questions.