Islamabad-

Police in the Pakistani port city of Karachi said on Friday that two suicide bombers attacked a truck carrying five Japanese autoworkers, but they all escaped unharmed.

Auto workers were sent to an industrial area in Pakistan’s commercial capital early in the morning and their bulletproof vehicles were attacked, a senior police officer told reporters.

Citing a preliminary investigation into the early morning violence, Karachi Police Regional Deputy Inspector General Azfar Mahsar said, “One terrorist approached the van and blew himself up, while another terrorist opened fire on the van.” He added, Two security guards escorting the Japanese workers returned fire and killed the bomber’s accomplice.

Mahsar said police also recovered the remains of the suicide bomber from the attack site and were currently investigating the identities of the two attackers.

A police statement later said: “All foreign guests are safe. Thank God.” The attack injured a guard and reportedly several bystanders.

The office of Pakistani Prime Minister Shehbaz Sharif issued a statement in Islamabad condemning the attack and praying for a speedy recovery for the injured.

No group immediately claimed responsibility for the attack in Karachi, the country’s largest city and capital of the southern province of Sindh.

The violence came a day after militants ambushed and killed six customs officials in restive Khyber Pakhtunkhwa province.

A team from the Customs Intelligence and Investigation Directorate was conducting an “intelligence-based” operation in the militant-hit Dera Ismail Khan area when their vehicle came under attack, officials said on Thursday.

The shooting killed customs officers who were fighting militant networks smuggling weapons into the region and surrounding provinces bordering Afghanistan.

Last month, a suicide bomber rammed a car packed with explosives into a convoy of Chinese engineers and workers in the province’s Kohistan region. The attack killed five Chinese citizens and their Pakistani driver.

The foreigners are building China’s multibillion-dollar Dasu Dam on the Indus River, Pakistan’s largest hydropower project.

Islamabad says fugitive leaders and fighters of the anti-Pakistan militant group have sought refuge in Afghanistan and intensified cross-border attacks since the Islamist Taliban regained control of the neighboring country.

The Taliban deny the accusations, saying they will not allow anyone to use Afghan soil to threaten neighboring countries, including Pakistan.