At least 15 people were killed and over 30 others injured when a bomb hit a bus stop in Pakistan' s northwest city of Peshawar on Thursday morning, reported local Urdu TV channel ARY.

Local media quoted police and rescue sources as saying that at least 15 vehicles nearby the blast site were completely destroyed and several dozens vehicles were partially damaged.

Bomb disposal squad said that an estimated 40 kilograms of explosives were used in the attack.

Police have arrested two suspects on the site. Identities of the arrested are not known yet.

Shortly after the blast, the Pakistani Prime Minister Yusuf Raza Gilani issued a statement strongly condemning the attack and the Pakistani President Asif Ali Zardari has demanded an immediate report over the blast.

No group has claimed the responsibility for the bomb attack yet.

Capital City Police Officer in Peshawar Imtiaz Altaf told local media that the bomb attack took place at about 11:00 a.m. local time when a bomb planted inside a car parking at the bus stop on the Kohat road of the city was detonated by unknown people through a remote control device.

At least two children were among the killed and all the injured people have been shifted to Lady Reading Hospital, the largest blast victim treatment hospital in the city. Hospital sources said that at least ten injured people admitted to the hospital were in critical condition, indicating a further possible rise in the death of the blast.