Tehran: Iran has expelled three Kuwaiti diplomats in a tit-for-tat move after the Gulf emirate said it would throw out three Iranian diplomats in a row over spy allegations, the website of state Press TV said on Sunday.

Kuwait's foreign minister said on March 31 three Iranian diplomats should be expelled in retaliation for what Kuwait says was an Iranian spy ring there. Press TV said the expulsions took place on April 2.

Last month, a Kuwaiti court sentenced three men, two Iranians and a Kuwaiti, to death for being part of an alleged Iranian spy ring in a case that has strained relations between Kuwait and Tehran.

Kuwaiti media said in May 2010 that authorities had detained a number of people, Kuwaitis and foreigners, suspected of spying for Iran. Media reports said they were accused of gathering information on Kuwaiti and US military sites for Iran's Revolutionary Guards.

Iran's relations with its Gulf Arab neighbours have soured since popular uprisings were suppressed by government forces. The Arab states have accused Iran of interfering in their affairs after Tehran objected to the despatch of GCC troops to help Bahrain put down protests.

Iran has denied the spying charge and says it avoids interference in other countries' domestic issues. Gulf Arab countries are concerned over what they see as the ambition of Iran to extend its influence in Arab countries.