The phrase "authorities in both" is correct and usable in written English.
It can be used when referring to the governing bodies or organizations in two different contexts or areas.
Example: "The report highlights the collaboration between authorities in both education and health sectors to improve community well-being."
Alternatives: "regulatory bodies in both" or "officials in both".
We need everybody's action; police here, police in Colombia, the authorities in both countries and the consumers too.
Various offices are pleading for gas masks, but the authorities in both houses are warning they may not be useful.
The Wanda-AMC combination is subject to approval by authorities in both the United States and China.
(Autonomy officials have denied the allegations, which are being investigated by authorities in both the United States and Britain).
England and South Africa are the front-runners to step in, and cricketing authorities in both countries yesterday expressed willingness to do so.
"We have raised his case with the Egyptian authorities in both London and Cairo and underlined the need for a full and transparent investigation.
Immigration authorities in both Japan and South Korea have set up temporary preclearing centers so that both Inchon and Narita can handle the big extra crowds of foreigners.
It worked with authorities in both the United States and Europe to reach a deal rather than fight a desperate legal action.
Water extraction authorities in both Washington, DC, and New York have also found it cheaper to pay for natural filter beds to handle water contamination than to build concrete ones.
Full appropriate Institutional Review Board ethical approval was obtained from Local Health Authorities in both sites.
Focus groups recommended that Somali migrants became residentially stable after about 5 years.b Full appropriate Institutional Review Board ethical approval was obtained from Local Health Authorities in both sites.
