CHENNAI: The city police on Thursday searched three star hotels where doctors appeared for the Professional Linguistic Exam Board exam after a message via Interpol about a bomb threat mail from Afghanistan. It turned out to be a hoax. An officer quoted the mail as saying: “In revenge for the UK not doing enough for Afghanistan, bomb explosions will take place today at several places in centres across the world. The world needs doctors at this time and we will ensure the UK doesn't get any. Insha Allah we will succeed”. Police in cities where the PLAB exam was held including Bengaluru, Chennai, Hyderabad, Kolkata, Mumbai, New Delhi and Colombo were alerted. Chennai police checked three hotels but didn't find anything suspicious.