A seventh World Vision worker in Pakistan has died after the office was attacked last week by gunmen, the Christian humanitarian agency announced Tuesday.

Imtiaz John, 34, served as a field coordinator with World Vision since 2006. He passed away Sunday, leaving behind a wife, a four-month-old baby and an extended family who depend on him for financial support.

In total, seven local staffs working for children and displaced communities in North Western Pakistan have died following Wednesday’s attack on the World Vision office in Mansehra District, north of the capital, Islamabad. The staff members who died from the violent act range in age from 23 to 43 years old.

“Our staffs are motivated by a straightforward interest in providing a better life for children,” said Charles Dokmo, World Vision’s regional vice president, in response to questions about what motivated the militants’ attack.

“Where extremists teach hate, our staff work with mothers and fathers to help needy children; where extremists sow violence, our staff work with farmers to plant the seeds of a more prosperous community, and where extremists encourage intolerance, our staff nurture respect for human life and human dignity,” Dokmo stated.

As many as 15 gunmen arrived in pick-up vehicles last Wednesday and opened fire on the office. World Vision said the attack was unprovoked and there was no prior warning.

One injured World Vision staff member remains hospitalized.

Investigation on the attack is underway, but so far authorities have not been able to identify a specific motive for the violence. In general, local militants carry out random acts of terror to destabilize the region and create fear among residents.

Despite the attack, World Vision will continue to operate its life-saving health activities in the North West region of Pakistan but has temporarily suspended other programs.

A global memorial service will take place Wednesday to remember and honor the Pakistani staff members who have passed away. All World Vision offices will participate.

World Vision has worked in Pakistan since 1992. Initially, the agency focused on relief intervention but expanded its work in 2001. It began collaborating with other aid groups on emergency relief assistance and community development initiatives in the North West Frontier Province and Punjab Province. World Vision further expanded its operations in Pakistan after the country’s devastating earthquake in October 2005.