Two Kuwaitis have been arrested in Abadan, southwest Iran, on suspicion of spying and illegal entry, an Iranian television channel has reported.
"Two Kuwaitis have been arrested in possession of spying materials," said Bahram Ilkhaszadeh, a local official in the town who spoke to Iran's Arabic-language satellite channel Al-Alam.
A member of parliament for Abadan, Abdollah Kaabi, also quoted by Al-Alam, said the pair were "arrested two days ago and they entered Iran illegally", without giving other details.
Ties between the two Gulf neighbours were strained after a Kuwaiti court in March sentenced three people to death and two others to life in prison after convicting them of being members of an Iranian spy ring.
The case led to a tit-for-tat expulsion of diplomats but ambassadors and diplomats returned to the two capitals following a visit to Kuwait City by Iranian Foreign Minister Ali Akbar Salehi on May 11.
Kuwait and the other Sunni-ruled Arab monarchies of the Gulf have repeatedly accused mainly Shia Iran of meddling in their internal affairs and of inciting Shia-led protests which rocked Bahrain earlier this year.
Manama crushed the pro-democracy protests in mid-March with the help of troops from other Arab states in the region, prompting condemnation from Iran.