Three suicide bomb attacks killed at least 52 people in Pakistan on Thursday, as a militant backlash intensified following the army's storming of a radical mosque in Islamabad.
A wave of bomb attacks has swept across Pakistan, killing more than 160, since the assault nine days ago on the Lal Masjid or Red Mosque complex, a militant stronghold.
At least 30 people were killed on Thursday when a car bomber, apparently targeting a vehicle carrying Chinese workers involved in mining activities, rammed into a police van escorting them in the southern town of Hub.
The Chinese were unhurt but all seven policemen in the van and 23 bystanders were killed. Twenty-eight people were wounded.
Another seven people, including policemen, were killed by a car bomb in the far northwestern city of Hangu on Thursday.
The third attack killed at least 15, including two children, at a mosque in an army training centre at a military cantonment area of Kohat, according to officer Mohammad Riaz at the police control room in the North West Frontier Province town.
"The explosion occurred as people were about to offer evening prayers, it was apparently a suicide bombing," he said.
The attack in Hub, at the border of Baluchistan and Sindh provinces, was the biggest of the latest wave of violence and the first in southern Pakistan.
"I saw flames all around me after a big bang. It appeared as if cars were flying in the air," Mohammad Raheem, 17, a labourer injured in the blast, told Reuters in a Karachi hospital.
"There were cries and screams all around. After that I don't know what happened. I just fainted."
Chinese workers have been targeted in the same region by Baluch separatists in the past, but police suspect the latest attack was more to do with the storming of the mosque.
"We believe it is part of the recent attacks carried out by Islamist militants," Tariq Masood Khosa, police chief of Baluchistan, told Reuters.
President Pervez Musharraf said on Wednesday he had no intention of declaring a state of emergency to counter the growing insecurity, and gave assurances that elections due later this year would go ahead as planned.
Karachi's stock market had gained almost 40 per cent since the beginning of 2007, but the escalating violence has lopped close to 6 per cent off the main index in the past two days.
A cleric in the southern city voiced fears of civil war if Musharraf stepped up his fight on militants in the northwest.
"Musharraf has chosen a dangerous path," said Mufti Muhammad Naeem of Karachi's largest Islamic school. "I think this situation could blow up in an all-out civil war."
The government said 102 people had been killed in the storming of the Lal Masjid. Many victims came from the northwest and were followers of clerical brothers advocating a militant brand of Islam reminiscent of the Taliban in Afghanistan.
The car bomber who blew himself up at a police training centre in the northwestern city of Hangu timed his attack to coincide with the arrival of a group of young recruits.
"The attacker tried to crash through the gate. He blew himself up as security guards at the gate tried to stop him," said Fakhr-e-Alam, top administration official of the city.
Hangu, which itself has a history of sectarian violence, is close to the lawless tribal regions on the Afghan border, known to be hotbeds of support for Al-Qaeda and Taliban militants.
Many Al-Qaeda fighters fled to Pakistan's tribal areas after US-led forces toppled the Taliban in Afghanistan in 2001.
At the same time as militants are believed to be avenging the mosque assault, pro-Taliban fighters have abandoned a peace pact in North Waziristan, raising fears of a resurgence in violence in the conservative northwest. Authorities on Thursday sent tribal elders to the militants in a bid to save the pact.
(Additional reporting by Imtiaz Shah in Karachi, Gul Yusufzai in Quetta and Sami Paracha in Kohat)