The New York Blood Center has declared a blood emergency after a 30% drop in donations in the last few weeks.

It is urging New Yorkers to roll up their sleeves donate blood.

It says blood, platelets and plasma are urgently needed to support patients undergoing surgeries, cancer treatments and trauma care.

One donation can save up to three lives, according to the center.

To encourage donations, the center is offering a free pint of Van Leeuwen ice cream to anyone who donates before the end of the month.