KARACHI, May 9: Police on Thursday groped in the dark, trying to figure out what kind of explosives had been used in Wednesday’s suicide bombing which left 14 dead and 18 wounded, and rounded up suspects all over the city.

While the police have so far registered no case in this connection, Sindh police chief Syed Kamal Shah told Dawn that the debris at the explosion site was being carefully examined to determine the exact quantity of explosives used.

“The bomb might have weighed more than what was initially assessed by the officials of the bomb disposal squad,” the provincial police chief said.

According to the initial assessment of the bomb disposal squad, the explosive device used in Wednesday’s bombing in front of Sheraton weighed about three kilograms.

The explosion was so intense that the car used in the suicide bombing turned into a hunk of twisted metal. Only the car’s engine and transmission box could be identified.

Mr Shah said the police had so far not sought foreign assistance for the probe into the suicide bombing and was conducting the investigation along scientific lines.

“Police officials have been inspecting the site of the explosion repeatedly, as the crucial evidence from here will lead us to those responsible for the killing.”

However, the provincial police chief admitted that so far a breakthrough had eluded the police.

Sources said that foreign investigation teams were due shortly, that was why on Wednesday night the police had erected tents around the site of the incident to preserve the forensic evidence.

They added that following the blast over a dozen officials of various intelligence agencies and diplomatic officials from various countries visited the blast site.

The officials from the French consulate had also inspected the site on Wednesday night.

Meanwhile, the police arrested over a dozen people during nightlong raids in different parts of the city on Wednesday night.

Police sources said that most of the arrested persons belonged to the outlawed religious groups.

However, a senior police officer termed them as routine arrests.

Another senior police official said that some people had been picked up from different parts of the city, but they are being interrogated and no one had been formally arrested.

Police sources said the woman who had died in Wednesday’s explosion had been identified on Wednesday by her grandson at the Edhi morgue. Her name was Mion Begum.

TRAFFIC: In their bid to beef up security, the police blocked various roads on Thursday.