"Luckily there was no serious damage," Pervaiz Rathore, the police chief of Pakistan's second-largest city, said.

Kamal Hyder, Al Jazeera's correspondent in Pakistan, said the explosives were planted in a nearby drainage channel .

"The explosions were meant to send a message rather than wreak havoc," our correspondent reported.

"[But] there is a big question mark remaining as to who could have planted the bombs."