The UN's envoy to Iraq has warned that "systemic violence is ready to explode at any moment", as a fresh wave of attacks killed at least 24 people, BBC News reported.

Martin Kobler urged Iraq's political leaders to "engage immediately to pull the country out of this mayhem".

There has been a recent upsurge in violence across Iraq amid rising sectarian and political tension.

Several car bombs targeted different areas of the capital, Baghdad, and the northern city of Mosul on Thursday, May 30. Five bombs killed 21 people in Baghdad and wounded dozens, officials said. In Mosul, three policemen were killed in an early morning suicide attack.

The dramatic escalation in attacks in recent weeks has raised fears of a return to the levels of sectarian violence seen in 2006 and 2007, in which thousands died.

This week alone, more than 60 people were killed in attacks targeting main Shia areas of Baghdad on Monday. A further 25 deaths were reported in bombings in the city on Wednesday.

The UN has said more than 700 people were killed in April - the highest monthly toll in almost five years. That would take the toll from the last two months well over 1,000 victims.