KARACHI - Police are investigating the events surrounding bombings of 9th and 10th Muharram that panicked mourners and law enforcers in the city. No headway has been made so far but investigators believe that the two assaults were carried out by a single outfit. According to a Bomb Disposal Squad officer, the bomb used in Abyssinia Line was a timed-device and carried 8-kg explosive material, while the other used in Kala bridge area contained 3.5 kilos of explosives and was detonated remotely. The BDS official further said that both the bombs were manufactured locally. SHO Jahangir Mahar said the two attacks were quite similar which indicated that a single terrorist group was responsible. The assault on 9th Muharram had been portrayed as a gas cylinder explosion before the BDS confirmed that it was a bombing. An improvised explosive device (IED) planted in a shop near Abyssinia Line of Lines Area went off soon after a Muharram procession passed the point late on Monday night. The bomb planted on Kala bridge was to target buses carrying mourners. It left a crater in the middle of the bridge when detonated. Luckily, no serious damage was caused. Four passers-by, namely Manzoor Hussain, Rasheed, Iftikhar and Kaneez, were wounded in the second attack. They were immediately ferried to the Jinnah Postgraduate Medical Centre for treatment. The bombs exploded with a loud bang that could be heard in the distance of 5-km. Cases have been registered against unidentified criminals under the Anti-Terrorism Act and Explosive Act in the Defence and Brigade police stations.