A、A labor strike on Wednesday. B、A political riot by the crowd. C、A bomb explosion on a bus. D、A car crash in Pakistan. C新闻的主旨大意

A bomb exploded on a crowded bus on Wednesday in the northwestern Pakistan town of Peshawar, killing 15 and injuring 30. Most of the victims were government employees. Video of the attack showed the explosion destroyed the bus. One eyewitness said, “The roof of the bus was completely blown off by the bomb. I saw many dead bodies and severely injured people being rushed to the hospital.” A police investigation concluded the bomb was hidden under a seat in the bus. An organization close to the Pakistani Taliban said it carried out the attack. The organization said the bombing was revenge for death sentences given to 13 of its fighters on Tuesday, according to Al Jazeera. The town of Peshawar has witnessed violence in the past. Bombings and shootings by the Pakistani Taliban have taken place there in the past months.
1. What is the news report mainly about?
2. Where was the bomb hidden?