Paraguay reported its first two cases Wednesday of babies born with microcephaly linked to the Zika virus, which is blamed for a surge in the birth defect across Latin America.

"The central laboratory confirmed the birth of two babies with microcephaly caused by Zika," health ministry official Agueda Cabello told a press conference.

Since Zika, a mosquito-borne virus, was detected in Latin America last year, health authorities have sounded the alarm over a sharp rise in the number of infected mothers giving birth to babies with microcephaly, or abnormally small heads.

The World Health Organization has declared an emergency over the apparent link between the virus and the potentially debilitating or deadly .

Brazil has been the country hardest hit, with more than 1,000 confirmed cases of microcephaly blamed on Zika.

Spain reported the first case Monday of a baby born in Europe with microcephaly linked to Zika. The mother had caught the virus during a trip abroad, though authorities did not say where.

Zika, which causes flu-like symptoms and a rash, is mainly transmitted by the Aedes aegypti mosquito. It has also been shown to spread through sexual contact.