An explosion jolted the minister's block of the civil secretariat here on Saturday afternoon, but there were no casualties. Capital City Police Officer Parvez Rafi Bhatti said that two suspects had been arrested after the explosion, which occurred in a toilet in the minister's block on the third floor of the building. There were no ministers in the building at the time, but other employees were present. Bhatti said the suspects were on the record of entrants to the secretariat from the main gate and the time of their entrance tallied with the time required to install the bomb with a timer.He said that the officer in charge of security at the civil secretariat, a deputy superintendent of police, was suspended and an inquiry had been ordered into the incident. He said that officials were trying to find loopholes in security at the building, which is located on a main road near Governor's House and Chief Minister's House. These loopholes included the improper searching of vehicles, he said. Last week 11 people including an army soldier were killed when a powerful bomb exploded at a crowded market place in Quetta. And last Sunday, police defused rockets primed to go off in a nearby locality.