Iraq summoned Iran's ambassador on Thursday to hand over a note of protest over the shelling of Iranian-Kurdish opposition groups in the country’s north, killing at least 13 people.

Ambassador Mohammad Kadhim Al Sadiq was handed a "strongly worded note of protest", Iraqi Foreign Ministry spokesman Ahmed Al Sahaf said.

The Islamic Revolutionary Guard Corps, a branch of Iran's armed forces, launched 73 ballistic missiles and 20 drones laden with explosives at Iraq's Kurdistan Region on Wednesday.

One of the drones was shot down by the US military after it appeared as a threat to American forces stationed in the regional capital Erbil, the Pentagon's Central Command said.

On Thursday morning, Iranian artillery hit the Sedekan area outside Erbil, a security official said. There was no immediate information on casualties or damage.

Iran has accused the Iranian-Kurdish groups of involvement in nationwide anti-government protests over the death of a young woman in police custody.

Mahsa Amini, 22, who died after being arrested by morality police in Tehran, was from Iran’s western Kurdish region, which borders Iraq.

Iran says armed Iranian-Kurdish dissidents are fanning the unrest, particularly in the north-west where most of Iraq's roughly 10 million Kurds live.

According to the counter-terrorism service in Iraqi Kurdistan, Iran launched a series of attacks from 1.15am on Wednesday that targeted the Azadi Kurdistan Party, the Democratic Party of Iranian Kurdistan and the Toilers of Iranian Kurdistan, as well as camps housing Iranian Kurds.

The attacks were carried out in four stages in Erbil and Sulaimaniyah province, the statement said.

“These attacks targeted public places such as kindergartens, schools, hospitals and health centres, houses, cars and event halls,” it added.

At least 13 people were killed, including a pregnant woman, and 58 others wounded, the majority of whom were young children, teachers, students and journalists, it said.

Iraq's note of protest said it "condemns this crime in continuous aggression by the Iranian forces against Iraq's sovereignty and territorial sanctity", the Foreign Ministry said.

Iran's attack drew local and international denunciation.

The Foreign Ministry said the attack was a “dangerous development that threatens Iraq's security and sovereignty”.

The Kurdistan Regional Government said Iran's actions “under any pretext are an incorrect stance, which promotes a misleading interpretation of the course of events”.

US State Department spokesman Ned Price condemned the attacks as an “unjustified violation” of Iraqi sovereignty.

The UN mission to Iraq said the country "rejects the notion that it can be treated as the region’s 'backyard' where neighbours routinely, and with impunity, violate its sovereignty".

It said "rocket diplomacy is a reckless act with devastating consequences. These attacks need to cease immediately".

Wednesday's attacks were the third time Iran has hit targets in Iraq since protests over Amini's death began. The IRGC also launched drone and artillery strikes against Kurdish positions on Saturday and Monday.

Amini was arrested for allegedly breaching Iran's strict rules on wearing the hijab and modest clothing for women.

The protests have spread across more than 50 cities, towns and villages in Iran, including Tehran, since her death on September 16.

Iran's Fars news agency, linked to the IRGC, on Tuesday said “around 60" people had died in the protests. But the Oslo-based Iran Human Rights group says at least 76 have been killed so far.

In an interview with state TV on Wednesday, Iran's President Ebrahim Raisi described the protests as “chaos” and accused foreign powers of stoking the unrest.

Also on Thursday, four rockets landed around the Iraqi capital's Green Zone, home to government buildings and foreign missions, Reuters reported, citing Iraqi police.

The missiles were fired from eastern Baghdad, police said. There were no immediate reports of casualties from the strikes and no claim of responsibility.

A similar attack on Wednesday wounded seven members of the Iraqi security forces in the Green Zone and appeared to add a new dimension to a contest among power-hungry politicians.

Rocket attacks on the Green Zone have been regular in recent years but they are normally directed at western targets by Iran-backed militias.

Those attacks have been rare in recent months. Wednesday's attack took place as the Iraqi Parliament was holding a vote to confirm its speaker.

Iraq is going through a prolonged political stalemate that has left the country without an active government for nearly a year since a bitterly disputed election result and mounting violence.

The national elections last October were the fifth parliamentary vote for a full-term government since the 2003 US-led invasion that toppled Saddam Hussein.