At least 65 people were killed and more than 100 injured in a series of bomb attacks across the Iraqi capital, Baghdad, Wednesday.
Police say the blasts occurred in predominantly Shiite areas of the city, and appear to have been coordinated.
At the same time, Iraq's Prime Minister, Nouri al-Maliki, has put Iraq's security forces on high alert because of the threat of a US-led attack on neighboring Syria.
There are close connections between the violence in both countries, says Jane Arraf, and there's a risk of escalation.
Arraf reports from Iraq for Al Jazeera English and the Christian Science Monitor.
The attacks in Iraq are largely conducted by Sunni extremists, linked to al-Qaeda.
During the American war in Iraq, Sunni insurgents enjoyed shelter and support in neighboring Syria. And today there are strong connections with the Sunni rebels fighting in Syria.
In fact, says Arraf, Iraqis are fighting on both sides in Syria.