A daycare worker was charged in Spain over claims that six toddlers at the center where she worked were given tranquilizers, Sky News reported Thursday.

The children, aged from just a few months to two years old, were taken to hospital earlier this month after showing signs of drowsiness at the daycare center in the northwestern port of Vigo, Spanish newspaper El Mundo reported.

Four of the children spent several days in hospital but all six recovered and are now well.

The cause of the children's drowsiness was at first a mystery, with a chemical or gas leak cited as possible reasons.

But tests on the children found traces of benzodiazepines, often prescribed to manage anxiety, panic and sleep disorders, investigators said.

An employee was charged with acts endangering public health, they added.

The judge who is leading the investigation into the case is expected to question other staff members at the center after the Easter break.

SOURCE LINK: Sky News