Attacks on Shiites in Baghdad and north of the capital killed four people on Friday, after the conclusion of the Eid festival and as Al-Qaeda claimed a series of attacks earlier in the summer.

In the deadliest attack, two explosions struck the predominantly Shiite neighbourhood of Sadr City in north Baghdad at around 12:30 pm (0930 GMT) as worshippers were gathering for prayers on the Muslim day of rest.

Three people were killed and at least eight were wounded, according to medics at nearby hospitals and an interior ministry official.

A police officer at the scene of the blasts said they were caused by mortar fire. All spoke on condition of anonymity.

Among the wounded was Nasser al-Saadi, an official in the movement loyal to anti-US cleric Moqtada al-Sadr, the medics said.

Another person was killed and three others wounded by a roadside bomb targeting the home of a Shiite family in the town of Khan Beni Saad, 30 kilometres (18 miles) north of Baghdad, a police colonel and a medic at the main hospital in provincial capital Baquba said.

Officials in the main northern city of Mosul, meanwhile, on Friday morning found four bodies, all of men in their 30s who had been shot in the head and chest. It was unclear why they had been targeted.

Both police First Lieutenant Mohammed al-Juburi and doctor Mahmud Haddad at Mosul General Hospital said the men appeared to have been killed late on Thursday.

The violence came after the conclusion of the three-day festival of Eid, which had been relatively calm after violence during the Muslim fasting month of Ramadan left 409 people dead across Iraq.

Friday's unrest takes to 242 the number of people killed in attacks nationwide this month, according to an AFP tally based on reports from security and medical officials.

On Wednesday, Al-Qaeda's front group in Iraq in a statement posted on jihadist forums claimed to have carried out a series of attacks, mostly on security forces in the western province of Anbar in June and July.

The 43 attacks purportedly carried out by the Islamic State of Iraq (ISI) were largely in the form of bombings and shootings against Iraqi soldiers, police and anti-Qaeda militiamen known as the Sahwa, according to the statement.

It comes after the ISI declared a campaign last month to retake territory it had abandoned in the years since the peak of Iraq's sectarian bloodshed between 2006 and 2008.

Also in the early hours of Friday, six people were killed and 10 injured by a fire at a nightclub in central Baghdad, security and medical officials said. The blaze appeared to have been caused by an electrical fault.