KYIV, Ukraine — Ukraine said that it has expelled two Hungarian diplomats on Friday, hours after the country’s main security agency said it had arrested two people on suspicion of spying for Hungary by gathering intelligence on Ukraine’s military.

The allegations of spying were met with anger in Budapest, where Hungary’s Foreign Ministry expelled two Ukrainian diplomats for what it said were Ukraine’s own espionage activities.

The Security Service of Ukraine said in a statement that two suspects, both former members of the Ukrainian military, had been detained as members of a spying network, and that they each face charges of treason, which is punishable by life imprisonment. Ukrainian Foreign Minister Andrii Sybiha later said that two Hungarian diplomats were expelled.

The activities of the suspected spies were focused on the western Ukraine region of Zakarpattia, which borders Hungary and is home to a sizeable Hungarian ethnic minority. Budapest and Kyiv have clashed over the rights of Hungarians in Zakarpattia, most of which was part of Hungary until the end of World War I.

— The Associated Press