Baghdad is once again on high alert after yesterday’s co-ordinated car bombings in Bab al-Sherji market killed at least 88 people and wounded 207, mainly Shiites. 

Seconds after one parked car exploded in a street bordering the market, a suicide bomber rammed the second car into a cluster of stalls and set off the second explosion. The two cars were reportedly packed with 220 pounds of explosives each.

The attack took place at midday, a peak shopping time, at one of the busiest bazaars in Baghdad where vendors sell DVDs, second-hand clothing and t-shirts, as well as fruit.

Hours later, in the predominantly Shiite town of Khalis in Diyala province, 50 miles north of Baghdad, a local market was bombed and then attacked with mortars, killing at least 12 people and wounding 29.

Monday’s death toll comes as Shiites observe the 10-day religious holiday of Ashura, which ends on January 30.

This is the worst carnage seen in the capital since five car bombs exploded in the Shiite slum of Sadr City on November 23 last year, killing 215 people and wounding a further 250. Those attacks also involved suicide bombers and parked cars loaded with explosives.

The same tactics were used less than a week ago at Mustansiriya University in eastern Baghdad, where a double-car bombing killed 70 people, mostly female students, and injured 170. Moments after a car bomb exploded at the university entrance, a suicide bomber drove into the fleeing crowd and detonated the second car bomb.

It has also been a particularly deadly three days for the US in Iraq, having lost 28 troops. This includes one soldier killed on Monday when a roadside bomb exploded in Nineveh province northwest of Baghdad. The US military also reported that twelve service members died on Saturday in Diyala province when their Black Hawk helicopter crashed. Although one insurgent group has claimed to have shot down the helicopter, the cause of the crash has not yet been confirmed.

There are suspicions that the spike in violence during the past week is a signal that Iraq’s insurgency is determined not to be put down by the forthcoming surge in US troops. This could also be a strategic attempt to destabilize the planned US-Iraqi security operations, by rushing them into implementation before comprehensive joint briefings are conducted and other preparations finalized.