At least five security personnel were martyred and 19 people injured in a blast near Thandi Sarak in district Sibi of Balochistan, officials said.

Medical Superintendent Civil Hospital Dr Sarwar Hashmi told Dawn.com that 16 of the 19 injured were security personnel.

He had earlier said that among the injured who were initially brought to the hospital, five were in critical condition and shifted to Quetta.

Meanwhile, a senior official of the Counter-Terrorism Department Sibi, Hafeez Rind, said the blast appeared to be a suicide attack; however, the investigation was underway.

The blast occurred near an open area where the annual Sibi Mela was being held.

"The blast took place 30 minutes after President Arif Alvi attended the festival in Sibi," Rind said.

Meanwhile, Balochistan Chief Minister Mir Abdul Quddus Bizenjo strongly condemned the blast and directed authorities to provide the best possible medical treatment to those injured in the blast.

Bizenjo said the blast was an attempt to sabotage the annual festival and overall peace in the province.

He vowed to thwart "all conspiracies against the province".

The chief minister directed the police to beef up security in Sibi and arrest those involved in the incident.

Last week, a suicide bomber had struck inside a Shia mosque in Peshawar's Kocha Risaldar area during Friday prayers, killing at least 56 worshippers and wounding 190 others.