The so-called Islamic State has claimed attacks at two Baghdad markets in which 20 people were killed.

A suicide bomber blew up a car at the entrance of Baghdad's main vegetable market, killing at least 13 people and wounding dozens, security officials and medics said.

Jamila is the main wholesale vegetable market in Baghdad and lies in Sadr City, a vast, mostly Shia, neighbourhood in the northeast of the capital which has been repeatedly targeted.

A few hours afterwards, a suicide bomber wearing an explosive vest blew himself up at a market in another mostly Shi'ite district, Baladiyat, killing seven, according to police and medical sources.

More than 80 people have been killed in just over a week in attacks in Baghdad and other Iraqi cities.

The most recent major attack claimed by IS was on 2 January - also in Sadr City - when a suicide bomber blew up a vehicle packed with explosives among a crowd of day labourers waiting for work, killing 35 people.

Meanwhile, Iraqi special forces battling IS reached the eastern bank of the Tigris river in Mosul for the first time today in a three-month, US-backed offensive to capture the city from the militants, who still control its entire western half.

Units of Iraq's elite counter-terrorism service (CTS) have fought their way to the eastern bank of the Tigris, spokesman Sabah al-Numan said.

It was the first time Iraqi troops in the city itself have reached the river, which bisects Mosul, since the offensive to drive out IS was launched in October. Iraqi forces already control the Tigris to Mosul's south.

They are not expected to push across the river without first recapturing the rest of the eastern districts, and in fact all the bridges have been taken out of service by air strikes.

But reaching the eastern bank shows the accelerated pace of the latest Iraqi advance, which has made daily gains since restarting 10 days ago.