Norway has expelled an Iranian diplomat in a dispute that comes a week after Iran ordered a Norwegian diplomat to leave Tehran.

In a statement Wednesday, the Norwegian Foreign Ministry did not identify the diplomat, but characterized the expulsion as a strong reaction to a similar move by Tehran several weeks ago.

The dispute erupted last month, when Oslo granted asylum to Iran’s former counsel-general, Mohammed Reza Heydari.  The Iranian quit his post in January to protest Iran’s deadly crackdown on opposition demonstrators in the Islamic republic a month earlier.

Heydari went into hiding immediately after his resignation, saying he feared for his life.