BAGHDAD: Two explosions in the Sadr City neighbourhood of north Baghdad ahead of Friday prayers killed three people and wounded at least eight, security and medical officials said.

The twin blasts struck at around 12:30 pm as worshippers were gathering for prayers on the Muslim day of rest, and came after the conclusion of the Eid festival on Thursday.

Medics at Al-Sadr General Hospital and Imam Ali Hospital, both nearby, said three people were killed and eight wounded in the attacks, while an interior ministry official put the toll at three dead and 16 hurt.

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.

Officials in the main northern city of Mosul, meanwhile, on Friday morning found four dead bodies, all men in their 30s who suffered gunshots to the head and chest. It was unclear why they were 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 Thursday evening.

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.

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.

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