KUWAIT (Reuters) – Kuwait on Wednesday condemned an assault on a Kuwaiti diplomat by unknown assailants in Iran as an “attack on Kuwait”, the state news agency KUNA reported.

“(This is) an attack on Kuwait, on international law and on Islamic values,” KUNA quoted Foreign Minister Sheikh Mohammad al-Salem al-Sabah as saying.

Iran on Wednesday voiced regret over the incident in which its state media said the diplomat was beaten up on Tuesday by unknown assailants.

“We are sorry about this incident and we are studying and investigating the details,” Iranian Foreign Ministry spokesman Mohammad Ali Hosseini said, quoted by the official news agency IRNA.

KUNA did not give details of the incident, over which Kuwait summoned Iran’s ambassador in the Gulf Arab state. Kuwait’s embassy in Tehran, contacted by Reuters, declined to comment.

Relations between the two Gulf neighbours have improved considerably from the 1980s when Kuwait and fellow Gulf Arabs sided with Iraq during its 1980-1988 war with Iran.

Kuwait said last week it would not allow its ally the United States to use its territory to launch any strike on Iran if a row over Tehran’s nuclear programme escalates.