SINGAPORE - The Singapore Red Cross is appealing for O+ blood type donors as blood bank levels have dropped below the healthy level needed to circulate to hospitals.

It made a Facebook post on Wednesday calling for people with blood type O+ to donate.

An average of 700 units of type O blood has to be maintained daily to circulate to hospitals. As of Wednesday morning, there were 473 units.

Red Cross blood donor recruitment programme head Elaine Tham said that the call was put out to help recover the healthy level of type O blood.

She said: "Today, we are not at the healthy level, so we would like to highlight to the community of this blood type to please come in this week to help to recover that level."

She added that blood collection usually slides over holidays and long weekends, because of donors travelling overseas. Blood stocks can dip as much as 20 per cent across all blood types.

Ms Tham said: "We have a full-fledged seven long weekends to manage, very different from last year or the year before."

People can donate blood at blood banks at the Health Sciences Authority building, Dhoby Xchange, Woodlands Civic Centre and Westgate Tower, as well as mobile donation vehicles (http://www.donorweb.org/singapore-bloodmobiles/).

Potential blood donors need to meet some basic requirements: http://www.redcross.sg/articles/save-lives