Iran's Foreign Ministry said on Sunday it would investigate reports of shelling in Kurdish areas in northern Iraq which Iraqi officials have blamed on Tehran.
Iraqi officials last month accused Iran of shelling Kurdish villages in Iraq's north-east. Iraqi Foreign Minister Hoshiyar Zebari said on Thursday the shelling threatened ties with Iran and said Baghdad had summoned Iran's envoy over the incidents.
"We have to investigate more about the truth of these reports," Foreign Ministry spokesman Mohammad Ali Hosseini said in the first official Iranian comment on the shelling. "What we are witnessing in our border area with Iraq is the activities of some terrorist groups who are using the presence of occupiers in this region to perpetrate acts of sabotage," he added during a weekly news conference.
Cross-border clashes occasionally occur as Iran and Turkey battle Kurdish separatist rebels operating from bases in Iraq's mountainous north-eastern region of Kurdistan.
Baghdad says hundreds of people were evacuated from villages due to the shelling. Kurdish PJAK guerrillas, who seek autonomy for Kurdish areas in Iran, are believed to shelter in the area.
"They (terrorist groups) cross the borders illegally. They have transferred a lot of weapons from Iraq into Iran and have caused some clashes," Hosseini said.
Ties between Iran and Iraq, both mainly Shi'ite Muslim, have improved since 2003 when US forces toppled Saddam Hussein, a Sunni Muslim who waged an eight-year war with Iran in the 1980s.
US officials say Iran is fomenting violence inside Iraq. Nevertheless, US and Iranian officials have held talks on Iraq in Baghdad since May, the most high profile meetings since ties were cut after the 1979 Islamic revolution.
Despite the talks, both sides continue to exchange barbed comments. US President George W. Bush said on Tuesday Iran's atomic plans, which Washington sees as a drive to make bombs, put the region "under the shadow of a nuclear holocaust".
Iran insists its nuclear ambitions are peaceful and says Washington is making accusations so it can prolong an occupation of Iraq which Tehran wants ended.
Asked if Iran would continue speaking to the United States amid such tensions, Hosseini said: "The Iraqi officials have stressed on numerous occasions that these talks (should) continue and have expressed satisfaction about the results of these talks ... It is important for us to continue these talks."