Seven people died and 34 were injured when a car bomb exploded near a busy intersection at the edge of Sadr City in eastern Baghdad.

In the northern city of Mosul, attackers gunned down a Nineveh province intelligence official in a drive-by shooting, killing him, police said. Four other police officers were also killed in the attack.

In a separate incident, gunmen killed two anti-al-Qaeda militiamen near Tikrit, north of Baghdad.

Over the past several weeks, there's been an increase in violence across Iraq. On Monday, at least 57 people were killed and 190 wounded in a wave of attacks in Baghdad and other cities, police said.

In April, Iraqi Prime Minister Nuri al-Maliki warned of attempts to return Iraq to "sectarian civil war".

He called on everyone worried about Iraq's future "to take the initiative, and not be silent about those who want to take the country back to sectarian civil war."

The current violence in the county, he said, “is an intrigue plotted for Iraq, so we call on the politicians to confront this plot by consolidating brotherhood among them and avoid harming their country.”

A wave of violence began on April 23 when militants invaded security checkpoints near the town of Hawijah in north Iraq, sparking clashes in which 53 people were killed.