MIDDLETOWN, Conn. — Police in Connecticut are investigating white powder that was found at a synagogue.

WFSB-TV reports a letter containing powder was discovered Wednesday at Congregation Adath Israel in Middletown. Middletown Mayor Dan Drew says the community isn't in danger.

Police believe the incident may be related to suspicious packages that were found at four downtown Hartford buildings last week. The structures included a state government building, two office buildings and the federal courthouse. No injuries were reported and at least two packages appeared to contain baby powder.

Prosecutors say 51-year-old Gary Gravelle is being investigated in connection with the Hartford threats. Gravelle was charged with violating the terms of his release from federal prison in 2015.