Pakistani paramilitary soldiers patrol in front of the United Nations office after a suicide blast in Islamabad, 05 Oct 2009A suspected suicide bomb blast hit the offices of the World Food Program in Pakistan's capital, Islamabad, on Monday, killing five people, including at least one foreigner. Several people were wounded.

Security officials blocked off the building in a high security zone in Islamabad, as teams with sniffer dogs entered the complex to check for more explosives.

World Food Program spokesman for Pakistan Amjed Jamal spoke to VOA by phone, shortly after the blast, saying, "What I can confirm is that there was a blast, there was something planted already in the office, which up, and that my colleagues are injured."

Officials say three Pakistanis and one Iraqi national are among the dead.

Security Stepped Up

Pakistani authorities say they have strengthened security in the capital following the attack.

No one has claimed responsibility, but militants have targeted U.N. offices in the past.

In June, a senior Pakistani officer with the U.N.'s refugee agency was killed in a botched kidnapping attempt near Peshawar.

Since his death, UNHCR has suspended the voluntary repatriation of Afghan refugees living in camps in Pakistan.

Jamal says that despite the violence, his organization will continue to help those in need in Pakistan. "I can confidently say such acts cannot hamper humanitarian work in Pakistan," he said.

The WFP offices are located on a street that already has high security due to other nearby United Nations offices. Also, across the main road is Pakistani President Asif Ali Zadari's civilian residence, which is a hub for political activity in the capital.