At least 50 people have been killed following a wave of car bombs and shootings in Shiite areas in and around Baghdad.

Around a dozen car bombs and assassinations across the Iraqi capital also left another 160 people wounded, with officials warning the toll could rise.

The attacks come on the 10th anniversary of the US-led invasion of Iraq.

All bar one of the strikes were carried out in Shiite neighbourhoods during morning rush hour.

"I was driving my taxi and suddenly I felt my car rocked. Smoke was all around," said Al Radi, a taxi driver caught in one of the blasts in Baghdad's Sadr City.

"I saw two bodies on the ground. People were running and shouting everywhere."

Security forces have since stepped up searches at checkpoints and closed off key roads.

Soldiers and police also established new checkpoints and unusually were searching government-marked vehicles that are typically allowed to pass uninspected.

No group immediately claimed responsibility for the violence, but Sunni militants often target Shiite civilians and government employees in a bid to destabilise the country.

Violence has spiked ahead of the anniversary of the 2003 US-led invasion, with 87 people killed in the past week, according to a tally based on reports from security and medical officials.

Britain-based Iraq Body Count has said that more than 112,000 civilians have been killed since the 2003 invasion.

Since the withdrawal, Iraq's military and police have been described by Iraqi and US officials as capable of maintaining internal security but not yet fully able to protect the country's borders, airspace and maritime territory.

AFP