A steady stream of families fleeing fighting in Ramadi and Fallujah is arriving at a checkpoint in Iraq's Karbala province, seeking shelter from the deadly violence.

As militants hold parts of Ramadi and all of Fallujah, in Anbar province, Sunni families are now seeking safety in the Shiite-majority Karbala province, in a country that has been plagued by sharp sectarian divisions.

Protesters took to the streets across Iraq on Friday to mark a "Day of Rage,” with thousands flooding Baghdad's Tahrir Square as seven protesters died in clashes with police in two northern cities.

Protesters in the capital were forced to walk to the rally site as security forces imposed a vehicle ban, a day after Prime Minister Nuri al-Maliki claimed the demonstrations were being organized by al-Qaida insurgents and loyalists of deposed dictator Saddam Hussein.

Two car bombs struck Shiite pilgrims Monday in an Iraqi holy city, killing at least 18 people as crowds massed for religious rituals marking the end of a 40-day mourning period for the Islamic sect's most beloved saint.

The blasts in Karbala were the latest in nearly a week of attacks that have killed at least 159 people. The uptick in violence has shattered a lengthy period of calm and raised anew concerns about the readiness of Iraqi forces to take over their own security ahead of a full withdrawal by the U.S. military.