The South African National Blood Service says it still needs more blood after its stocks dropped dangerously low last week.

The organisation's Ravi Reddy has thanked the donors who responded to the SANBS's calls to donate last week. But he says more is needed.

Reddy says the service will also be approaching schools.

He says once schools reopen they hope to have reached their normal five-day stock reserves by the end of the week.

The SANBS says it particularly needs more blood from group O donors.

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