The UN yesterday mourned the deaths of two of its staff killed during a suicide car bomb attack in a luxury hotel in Pakistan.

Aleksandar Vorkapic, a Serbian with the UN High Commissioner for Refugees, and Perseveranda So, a Unicef employee from the Philippines, were among the 16 people killed in the attack on the Pearl Continental hotel in Peshawar.

"This is an attack on the very humanitarian principles to which Persy was dedicated, and it is reprehensible and unacceptable," said Unicef executive director Ann Veneman in a statement released in Geneva. Identifying Persay as Unicef's chief of education in Parkistan, she said: "She will be greatly missed... Our hearts go out to her family and friends, in her home country of the Philippines and around the world, who share our loss."

Antonio Guterres, who heads the UN refugee agency, said Mr Vorkapic - married with three children - volunteered to be deployed last month to help civilians recently displaced by fighting in northwest Pakistan.

"He was on his first emergency mission and he gave his life serving others," said Mr Guterres. "All of us at UNHCR are devastated by this tragedy and we convey our deepest condolences to his family in Belgrade."

Attacks such as the one in Peshawar raised the "truly terrible dilemma" of meeting the needs of the vulnerable while at the same time ensuring the safety of humanitarian workers, he added.

Mr Vorkapic was the second UNHCR staff member to be killed in Pakistan in the past five months, while Ms Veneman said Persy had been with the UN Children's Fund since 1994.