Iran launched fresh strikes against Kurdish opposition groups based in Iraqi Kurdistan late Sunday, the groups and local officials said, the second such attack in a week.
Tehran accuses the groups of stoking unrest in Iran, which has been rocked by two months of protests sparked by the death of Kurdish-Iranian woman Mahsa Amini, 22.
Amini died in custody on September 16, days after her arrest by Iran's morality police for allegedly breaching the country's strict dress code for women.
Iran's "Revolutionary Guard Corps have again bombarded Iranian Kurdish parties", the counter-terrorism department of Iraqi Kurdistan said, without mentioning if there were casualties.
The Democratic Party of Iranian Kurdistan (PDKI) said Iran had targeted it with missiles and suicide drones in Koya and Jejnikan, near Arbil, the capital of Iraqi Kurdistan.
"These indiscriminate attacks are occurring at a time when the terrorist regime of Iran is unable to stop the ongoing demonstrations in (Iranian) Kurdistan," the PDKI, the oldest Kurdish party in Iran, said.
Iranian Kurdish nationalist group Komala said strikes had also targeted its installations in northern Iraq.
"Our HQ was once again attacked by the Islamic Regime tonight. We've been carefully prepared for these types of attacks & have no losses for the moment," it said on Twitter.
The US Central Command, which oversees US military operations in the Middle East, condemned the "illegal" Iranian strikes near Arbil.
"We condemn this evening's Iranian cross-border missile and unmanned aerial vehicle strikes," Centcom commander General Michael Kurilla said in a statement.
"Such indiscriminate and illegal attacks place civilians at risk, violate Iraqi sovereignty, and jeopardise the hard-fought security and stability of Iraq and the Middle East."
The Iraqi state news agency INA early Monday also reported on the attacks, referring to "Iranian missile and drone strikes" against "three Iranian opposition parties in (Iraqi) Kurdistan".
The new strikes come less than a week after similar cross-border attacks by Iran which killed at least one person.
Tehran accuses Kurdish-Iranian opposition groups based in northern Iraq of stoking the "riots" at home and has stepped up its attacks since the protests began.
Iran launched attacks in late September that killed more than a dozen people in Iraq's autonomous Kurdistan region.
Iraqi Kurdistan hosts several Iranian Kurdish opposition groups which have in the past waged an armed insurrection against Tehran.
In recent years their activities have declined, but the wave of protests in Iran has again stoked tensions.