QUETTA: A shutter-down strike is being observed in Quetta on Friday to mourn the killing of eight members of the Hazara community.

Markets and shops located in the main commercial areas of the city remained close owing to the strike.

The Hazara Democratic Party (HDP) and the Majlis-i-Wahdatul Muslimeen (MWM) had given the call of strike.

Earlier on Thursday, armed militants had opened fire at a passenger bus and killed eight members of the Hazara community.

More on this: Eight Hazaras gunned down in Quetta bus attack

The incident was followed by a suicide attack on Jamiat Ulema-e-Islam (JUI-F) Chief Maulana Fazlur Rehman that left two people dead and over two dozen others injured.

Explore: Two killed as JUI-F chief Fazlur Rehman escapes suicide attack in Quetta

A powerful blast targeting the vehicle of Frontier Corps (FC) personnel also left two people dead and 12 injured in the Qambrani road area of Quetta.

Take a look: Two killed, 12 injured as FC vehicle targeted in Quetta blast

Panic prevailed in the city in the aftermath of three major untoward incidents in which 13 people lost their lives and over three dozen others sustained injuries.

HDP and MWM, in separate statements, lamented that the provincial government of Balochistan had failed to protect the lives of citizens.

They demanded of the government to take effective measures to protect the members of the Hazara community in Quetta.

Majority of the citizens were confined to their homes on Friday owing to fear of untoward incidents whereas the flow of traffic remained thin on the roads of Quetta as a result of the strike.

Police and FC personnel were deployed at all sensitive parts of Quetta to avert any terror bid.

Meanwhile, police registered a case against unknown terrorists in relation to the attack on Fazl at the City Police Station.

Police sources told Dawn that the FIR was registered against unknown terrorists by the Station House Officer (SHO) at the City Police Station under the terrorist act.

30 suspects arrested in Quetta

Police and security forces conducted raids in different parts of Quetta and arrested 30 suspects in the aftermath of terrorists incidents.

A police officer told that Dawn raids were conducted on Sariab road, Brewery road and other parts of the city in connection with the bomb explosions and killing of eight members of the Hazara community.

"We recovered weapons from some of the suspects," he said. Besides police, personnel of other law enforcement agencies also participated in the raids.

"Innocent people would be set free after interrogation," he said.