SUNDAY’S blast at an imambargah in Karachi has heightened the immediate fear of the city’s residents that this year’s Muharram could be a bloody one. This was a nagging concern even before the weekend, both because of the record of violence during the holy month in past years and especially because of the sectarian violence that has plagued Karachi in the weeks leading up to it. Now, with an attack having been successfully carried out despite heavy security and several days still left to go before the particularly sensitive first 10 days of Muharram have passed, the spectre of another, and possibly more deadly, attack has become more real than ever.

As is the case every year, extraordinary security arrangements have been put in place for the month and volunteers from various communities and law enforcement are present at religious gatherings and processions in large numbers. And last year’s success in preventing large-scale attacks in the city shows that the authorities have built up some expertise in how to address the risks that Muharram brings. But Sunday’s blast showed that existing measures are still not enough. The attack, in which a motorcycle parked near the imambargah blew up, makes it clear that one obvious measure is to increase the radius around at-risk places of worship within which vehicles should not be parked, however inconvenient this might be for worshippers and nearby residences and businesses. But it also remains important to balance the need for security with citizens’ basic needs; this attack should not be taken as a reason for a blanket ban on motorcycles, on which over a million people in the city depend. Given this year’s record of sectarian violence across Pakistan, Sunday’s blast also begs the question of where else in the country an attack might take place and argues for an even greater effort in other sensitive areas as well. Karachi’s horrific Ashura blast of 2009 is still a recent memory, and this year’s trajectory suggests that law enforcement will have to step up their efforts to prevent another tragic event.