QUETTA, Dec 18: A powerful bomb exploded at the second floor of the ministerial block of the Balochistan Civil Secretariat on Saturday afternoon. The secretariat is heavily guarded.

The bomb was planted in the common bathroom of the second floor close to the offices of provincial Finance Minister Syed Ehsan Shah and Information Minister Matiullah Agha. The two ministers were not present in their offices when the explosion occurred.

No one was killed or injured in the blast as no person was present inside the bathroom or in the corridor at the time the bomb went off, official sources said.

The bathroom was badly damaged while the windowpanes of some offices at the same and other floors of the secretariat were smashed.

"It was a local made time device plated in the bathroom," Inspector-General of Police Chaudhry Yaqoob told reporters while visiting the explosion site in the ministerial block along with other senior police officers.

He said investigation was in progress into the explosion.

Meanwhile, the IGP has suspended the Deputy Superintendent of Police who is in charge of the security in the secretariat and has ordered an inquiry into the incident.

The civil line police have registered a case against unknown people for planting time device in the bathroom.

Police also detained two security guards posted at the main gate of the secretariat for questioning.

It was third time that bombs had exploded in the premises of the secretariat. Three years back two bombs were exploded close to the offices of the chief secretary and home secretary.

The home secretary office had been badly damaged in that blast.

Meanwhile, provincial ministers Mir Amanullah Khan Notizai and Maulana Faizullah strongly condemned the explosion in the ministerial block and termed it a conspiracy to defame the Balochistan government.