Russian security services are investigating two scientists for allegedly revealing state secrets, a probe that rights activists on Wednesday said highlights the chill that has fallen over Russian scientific research under President Vladimir Putin. Oleg and Igor Minin are the latest in a growing number of academics who have been targeted by the Federal Security Service for alleged espionage, revealing state secrets or misuse of classified information. The service, also known as the FSB, said in a statement that the two scientists published a booklet last year that outside experts determined contained classified information "related to the development of armaments." The evidence is being considered for possible prosecution, the FSB said. The brothers, who are physicists at the State Technical University in Novosibirsk, could not be reached for comment Wednesday.