The Archdiocese of Mexico is calling on local officials to improve security after a package containing explosives was mailed to the archdiocesan chancery.

“We will take basic security measures,” Father Hugo Valdemar, spokesman for the archdiocese, said. “This can’t be taken lightly as this is a threatening situation.”

On Nov. 25, Mexico City police investigated and removed the package, which appears to have been sent by local anarchist group Liberacion Total. The same group was responsible for setting an armored car on fire in the Mexican capital on Nov. 5.

Fr. Valdemar reported that the archdiocese's Cardinal Norberto Rivera is unshaken by the incident.