Out singer Lance Bass has criticized the FDA's ban on blood donations from gay men.

Bass, 38, made his comments on Monday, the day after a lone gunman broke a window in a Las Vegas hotel and started shooting at people attending an outdoor concert on the Las Vegas strip. At least 58 people died in the incident and 500 were injured. The gunman, reportedly, killed himself.

People almost immediately started lining up to donate blood for the victims.

“How is it STILL illegal for gays to donate blood??!!” Bass tweeted to his more than 418,000 followers. “I want to donate and I'm not allowed.”

In December, 2015, the FDA loosened guidelines, replacing a lifetime ban with a policy that allows gay men to donate blood if they have been celibate for 12 months. That is, even a gay man in a monogamous relationship cannot donate blood. (Bisexual men can donate blood, if they have not been intimate with another man in 12 months.)

Writer-activist Shane Bitney Crone also lamented the FDA's gay blood ban.

“It infuriates me that gay & bisexual men can be turned away from donating blood in Las Vegas because of the @US_FDA's discriminatory policy,” Crone messaged.