Blasts in three cities across Pakistan occurred within minutes of each other on Tuesday, killing at least four people and wounding 23, officials said.
Police official Tahir Ayub said the blasts appeared to be unrelated.
No one has claimed responsibility, authorities in the three cities said.
In the first incident, a suspected suicide bomber detonated himself on a deserted road on the outskirts of the northeastern city of Gujrat, police said.
"It seems like he may have set the bomb off by mistake," said police official Mudassar Ali.
Minutes later, a second blast went off in a bustling market area in Peshawar in northwest Pakistan. The bomb was placed on a motorcycle in the basement of a commercial building, police said. It killed one and injured 23.
In the third incident, unknown assailant fired a rocket into a busy market area in a Landi Kotal, a town in Pakistan's tribal Khyber Agency, said Khalid Mumtaz Khumbi, an administration official.
Three people died in the explosion, Khumbi said.FULL STORY