A series of coordinated evening blasts in Baghdad and other violence killed at least 67 people in Iraq on Tuesday, officials said, the latest day in a months-long surge of bloodshed that Iraqi security forces are struggling to contain.

Many of those killed were caught in a string of car bombings that tore through the capital early in the evening as residents were shopping or heading to dinner. Those blasts struck 11 neighborhoods and claimed more than 50 lives in less than two hours.

Deadly violence has been increasing in Iraq in recent months as insurgents try to capitalize on growing sectarian and ethnic tensions. The scale of the bloodshed has risen to levels not seen since 2008, when Iraq was pulling back from the brink of civil war.

The evening’s deadliest attack happened when two car bombs exploded near restaurants and shops in the northeastern Baghdad suburb of Husseiniyah, a Shiite area, killing nine people and wounding 32.

A row of restaurants was also hit in the largely Shiite eastern neighborhood of Talibiyah, killing seven and wounding 28. Another car bomb hit the nearby Shiite neighborhood of Sadr City, killing three and wounding eight, according to police.

At around the same time, authorities say back-to-back car bombs blew up near a police station in the western neighborhood of Sadiyah, a mainly Sunni area, killing six and wounding 15.

Another blast hit a central square in the commercial district of Karradah, killing six and wounding 14.

Car bombs also struck shopping streets in the religiously mixed western neighborhood of Shurta, killing five people and wounding 12; the southeastern Shiite neighborhood of Zafaraniyah, killing four and wounding 11; the southern Shiite neighborhood of Abu Dashir, killing two and wounding nine; the mostly Shiite New Baghdad area, killing six people and wounding 17; and the largely Sunni Dora neighborhood, killing two and wounding five, according to police.

Another car bomb exploded near an outdoor market in the Shiite village of Maamil, in the eastern suburbs of the capital, killing three people and wounding 41.

No one claimed immediate responsibility for the attacks, but coordinated car bombings and attacks on civilians and Iraqi security forces are a favorite tactic of the Iraqi branch of al-Qaeda.

Iraqi officials say the lawlessness roiling neighboring Syria — whose civil war has taken on sharp sectarian overtones, similar to those that nearly tore Iraq apart — is fueling the surge of violence in Iraq. Al-Qaeda’s Iraq arm and other Sunni extremist groups are fighting on the side of rebels trying to topple the regime of President Bashar al-Assad, which is dominated by Alawites, an offshoot of Shiite Islam.

“The recent threats of a military operation against Syria have encouraged the insurgents to wage more attacks inside Iraq. We have warned of this, but unfortunately, nobody is listening,” said Ali al-Moussawi, the spokesman for Prime Minister Nouri al-Maliki.