Story highlights Militants kill at least 44 people headed to Shiite religious commemoration

Other violence includes attacks on police station, city council building

Similar violence killed 21 people on Sunday

More than 8,000 people have been killed in Iraq in 2013, according to the United Nations

At least 70 people have been killed in another wave of the horrifying daily violence that is threatening to unravel Iraq, police officials around the country said.

More than 40 were killed in Baghdad Monday, many of whom were on their way to the Shiite holy city of Karbala. Another 17 pilgrims in Mosul were also killed by militants.

In Baghdad, at least 27 people were killed and more than 50 wounded when two car bombs exploded in quick succession near a procession of pilgrims making their way by foot to Karbala for the annual commemoration of the seventh century death of their Imam Hussein, a memorial called the Arbaeen.

Hussein was killed during a battle near Karbala for control of the Muslim nation after Mohammed's death in 632. Hussein's death led to a split between Sunni and Shiite Muslims.

The violence comes a day after at least 21 people died, including an anchor with al-Mousliya TV, in shootings and explosions, police said.

The U.S. Embassy in Baghdad issued a statement to condemn "the appalling acts of terrorism carried out against innocent victims in Iraq" in the last two days.

Also Monday, at least eight people were killed and four others wounded when a car bomb exploded outside a police station in Baiji, authorities in Tikrit told CNN. Militants freed at least 10 prisoners, authorities said.

Minutes after the initial explosion, gunmen stormed the station and clashes erupted between them and Iraqi security forces, police officials said.

Baiji is located about 200 miles (320 km) north of Baghdad in Salaheddin province.

In nearby Tikrit, militants stormed the city council building, clashed with Iraqi security forces and occupied the facility for a time, police officials in the city said. Several hostages were freed, but at least five were killed.

State-run Iraqia TV reported that an anti-terrorism unit freed some hostages and killed the militants.

More than 8,000 people have been killed in Iraq in 2013, according to U.N. figures.