A wave of attacks across Iraq killed at least 53 people on Thursday amid warnings that insurgents would mount deadly attacks ahead of the end of the holy Muslim fasting month of Ramzan.

Officials reported more than a dozen explosions and shootings in 15 cities and towns nationwide that also left more than 250 people wounded as Iraqis readied to celebrate the Eid al-Fitr festival.

The latest unrest takes the overall death toll from violence this month to 198, according to a tally based on security and medical sources.

The deadliest violence struck in and around Baghdad, where 26 people were killed in a series of bombings.

In the predominantly Shiite north Baghdad neighbourhood of Sadr City, 11 people were killed and 41 wounded by an evening explosion, while six people were killed and 26 wounded by a car bomb in the Husseiniyah district, also in the north of the capital, security and medical officials said.

North of Baghdad, gunmen with silenced weapons attacked a checkpoint in Massud, killing at least six soldiers and wounding seven others, security forces and medical officials said.

Three other people were killed and 11 wounded by twin blasts in the east Baghdad neighbourhood of Zafraniyah.

And in Tal Afar, north of Baghdad, a suicide bomber wearing an explosive belt killed six people and wounded 10 others, police Second Lieutenant Abed Ghayib and Dr Mohammed Tawfik said.

A series of attacks in Kirkuk province north of Baghdad, killed nine people.

In the town of Daquq, a suicide attacker blew himself up at an anti-terrorism department's compound, while in the province's eponymous capital, at least four car bombs were set off across the city -- including two at the offices of the state-owned North Oil Company.

"I came to investigate one of the attacks near the company compound," said police Colonel Abdullah Kadhim, head of Kirkuk city's sniffer dog unit.

"Suddenly, another bomb went off near me, and it damaged lots of cars and company property inside the parking lot."

Kadhim suffered wounds to his leg.

Provincial health chief Sadiq Omar Rasul put the toll from the attacks in Daquq and Kirkuk city at eight dead and 56 wounded. Provincial police Brigadier General Sarhad Qader said the victims included six police killed in the Daquq attack.

Also in Kirkuk province, two bombings near the home of a police captain in the town of Dibis killed his brother and wounded four others, including the captain himself, police and a doctor at nearby Kirkuk hospital said.

The violence in ethnically-mixed Kirkuk city was concentrated in its Kurdish-majority areas, and came on the anniversary of the founding of Iraq's most powerful Kurdish party, the Kurdistan Democratic Party.

In Kut, 160 kilometres (100 miles) south of Baghdad, a car bomb exploded on Thursday evening, police Colonel Dhargham al-Assadi said. Five people were killed and 70 others wounded, according to Dhia al-Din Jalil al-Ibboudi, the head of the Kut health directorate.

Attacks also struck Al-Garma, Al-Baaj, Badush, Tuz Khurmatu, Mosul, Taji, Khales and Baquba, leaving seven dead and dozens wounded.

A day earlier, 13 people were killed in attacks north of Baghdad.

On Monday, British security firm AKE Group warned that "terrorists in Iraq may be planning mass casualty explosive attacks against large gatherings of civilians to mark the end of Ramzan later this week."

"We haven't received any specific intelligence on the matter but they (insurgents) may be 'saving up' their willing bombers for the closing period of the month, due around 17-18 August," AKE analyst John Drake said.

Official figures put the number of people killed in attacks in July at 325, the highest monthly death toll since August 2010.