PESHAWAR, Pakistan — A roadside bomb hit a convoy of foreign diplomats visiting northwest Pakistan on Sunday, killing a police officer in their security detail, police said.

Zahidullah Khan, a police officer from the Swat district, told NBC News that the diplomats were on their way to a tourist resort “when a police van escorting their convoy was hit by an improvised explosive device.”

One police official died on the scene and three others were injured, he said, adding that the diplomats were visiting the Swat valley area on the invitation of local chamber of commerce.

Mohammad Ali Gandapur, the deputy inspector general of police in Swat, said all of the foreign ambassadors were safe and that the attackers had targeted a police vehicle.

Ambassadors from Indonesia, Portugal, Kazakhstan, Bosnia and Herzegovina, Zimbabwe, Rwanda, Turkmenistan, Vietnam, Iran, Russia and Tajikistan were among those in the convoy, police said.

Police made security arrangements for the foreign ambassadors and they were immediately rescued and moved toward Pakistan’s capital Islamabad, Khan said.

Offering sympathies to the families of those who died, Pakistan’s foreign ministry said in a statement that “all members of the diplomatic corps have returned safely to Islamabad.”

Pakistan’s President Asif Ali Zardari also condemned the attack. “Terrorist elements are enemies not only of the country and nation but of humanity itself,” he said in a statement issued by his office.

No one claimed responsibility for the attack.

Police and the Pakistani army closed roads and imposed a curfew in the area of the attack while they carried out a search operation.

Pakistani counterterrorist forces maintain a strong presence in the Swat valley, which has long been a hotbed of Islamist militant insurgency. The militants have stepped up their attacks since late 2022 after breaking a cease-fire with the government.

In 2012, Islamist militants shot and seriously wounded Nobel Peace Prize laureate Malala Yousafzai in the valley.

Mushtaq Yusufzai reported from Peshawar and Andrew Jones from London.