Iraq's north rocked by deadly blasts

Car bombs killed at least 18 and injured scores in Iraq's Kurdish-controlled cities of Kirkuk and Irbil on Saturday, as the United Nations called for immediate assistance to 15,000 Shia Turkmen, a minority group under siege by the Islamic State in northern Iraq.

The blasts come as Iraqi and Kurdish troops are fighting back an offensive by the Islamic State in the north and as sectarian attacks have deepened the country's crisis.

Two of three near-simultaneous car bombs in Kirkuk on Saturday exploded near buildings under construction that were used as observation positions by security forces, while the third struck the entrance to a market.

More than 100 people were injured in the Kirkuk blasts.

A police colonel said that the market blast may have been a suicide car bombing, while a doctor said that three security forces members were among the dead.

In Irbil, the capital of the autonomous Kurdish region, local television network Rudaw showed firefighters dousing the charred remains of a car outside a technical college.

Seven people were reported wounded but none killed in the blast.

While much of Iraq has been plagued by near-daily violence, Kurdistan's capital has avoided much of the deadly unrest.

The last major attack in Irbil was in September, when fighters launched a coordinated suicide and car bomb attack on the headquarters of the security services.

Earlier on Saturday, in capital Baghdad, a suicide bomber drove an explosives-laden car into the intelligence headquarters, killing six civilians and five security personnel.

Meanwhile, the prospect of massacre emerged again, with United Nations Iraq envoy Nickolay Mladenov expressing alarm at a Turkmen community besieged by the Islamic State in the Iraqi town of Amerli.

“The situation of the people in Amerli is desperate and demands immediate action to prevent the possible massacre of its citizens,” Mladenov said Saturday.

“I urge the Iraqi Government to do all it can to relieve the siege and to ensure that the residents receive lifesaving humanitarian assistance or are evacuated in a dignified manner,” he said.

Mladenov’s call comes after the harrowing rescue of thousands of Yazidis, a religious minority pursued by Islamic State fighters. They too were trapped for a several weeks on Mt. Sinjar, just west of Mosul in northern Iraq. Supported by U.S. airstrikes, Kurdish and Iraqi forces managed to deliver aid and rescue to the Yazidis, who faced near-certain slaughter by the Islamic State.

The Turkmen, a Shia ethnic minority who speak a Turkic language, have been under siege for several months and are running out of medicine, food and water. 

“Iraq’s allies and the international community should work with the authorities to prevent a human rights tragedy,” Mladenov said.

While making an appeal for national unity in Iraq and the inclusion of ethnic and religious minorities, top Shia religious leader Grand Ayatollah Ali al-Sistani also weighed in on the Turkmen crisis, speaking through his representative, Abdul-Mahdi al-Karbalaie, during Friday prayers in the Shia holy city of Karbala.

Al-Karbalaie called for urgent aid to be airlifted to residents of a small Shia town.

Al Jazeera and wire services. Zeina Khodr contributed reporting.