The Singapore Red Cross and the Health Sciences Authority called for continued blood donations three weeks ago. They put the low stocks down to a decrease in blood donations during the school holidays and increased use. Despite the appeal, a check with Donor Web's Singapore Blood Stocks Indicator reveals that blood stocks are still low.
Are you able to donate blood? See relevant pages at the Health Sciences Authority webpage. You can either donate at the National Blood Centre opposite Outram MRT or catch a bloodmobile at a location near you – just check the Donor Web Bloodmobiles Calendar (it is a Google Calendar you can copy) – in addition to CCs and organisations, I see that the bloodmobiles will be situated at various public libraries in the afternoons; it's never been more convenient.