ATHENS, Greece (AP) — Police in Greece say nine people have been received medical attention as a precaution after letters containing white powder were sent to five university campuses around the country.

Authorities say that none of the people examined — four postal workers and five university staff members — displayed any symptoms typically caused by harmful chemicals. Officials added that at least three of the letters appeared to have been sent from India.

All the letters, delivered or intercepted Wednesday and Thursday, have been taken to a state lab for examination.

The targeted administrative offices were at campuses on the island of Crete, Lesbos, and Corfu and well as in Athens and the central mainland city of Volos. Police said that all the universities were operating normally Thursday.