Updated 3.20 p.m.
The authorities have repeated an appeal for blood donation, first made this morning.
The Blood Donations Centre said there is an urgent need for 'O' Positive and 'A' Negative blood.
Spokesman Tony Micallef said the the situation had deteriorated since the first appeal this morning, even though a number of blood donors had come forward.
"Unless our reserves grow by tomorrow morning, some patients may not be given blood and some operations may have to be put off," he said.
Donations may by made at the centre, opposite St Luke's Hospital in Guardamangia, daily between 8 a.m. and 6 p.m. Donors are to produce their ID card.
www.blood.gov.mt