QUETTA: A cycle blast killed four people and injured another 20 in Quetta, the capital of militancy-hit Balochistan province on Wednesday, police said.

Syed Ahmed Mobeen, the Deputy Inspector General (Investigation) Quetta said unknown militants had planted around seven kilogram explosive materials in a cycle parked on Double Road area of Quetta.

"The explosive materials went off when there was crowd of people," he said. Double Road is considered to be one of the busiest areas of Quetta.

The Deputy Police Chief of Quetta said the strength of blast smashed glasses of nearby shops and houses in the area.

The shopkeepers pulled down the shutters of their shops soon after the blast which was heard far and wide in the city that has been plagued by sectarian violence and attacks by Baloch separatist groups.

"I was sitting in a mosque when the bomb struck," Bashir Ahmed an eyewitness told Dawn.com.

"The strenght of the blast smashed the windows of the mosque and there was dust everywhere," Ahmed said.

Rescue workers and police were quick at the scene and all injured were rushed to civil hospital Quetta for medical treatment.

Emergency was imposed in civil hospital Quetta to ensure treatment for the injured. Senior doctors and paramedics were called on emergency basis to treat the injured.

Dr. Nawaz Kibzai, the Medical Superintendent of Civil Hospital Quetta told Dawn.com that the condition of four of the injured was critical.

"Some of the injured are being operated," Kibzai said. There has been no claim of responsibility for the attack.

Bodies found in Dera Bugti

In another incident, a levies official who requested not to be named told Dawn.com that two bullet-riddled bodies were found in Zain Koh area of Dera Bugti on Wednesday.

The dead bodies were shifted to civil hospital Dera Bugti for post-mortem. "The dead bodies are yet to be identified," he said.

The recovery of dead bodies came a day after militants killed nine members of a family in the Loti Zain area of Dera Bugti. No one claimed the attack.