|PIC1|"Our belief is that only God is the judge and our place is to forgive and that's a difficult thing to do, but really, I think it's the right thing to do," remarked the devastated director of Youth with a Mission Denver in the US, Peter Warren, after the fatal shooting of two young staff members by an unidentified gunman on Sunday.

A lone gunman entered the YWAM training centre in the Arvada suburb of Denver, Colorado, in the early hours of Sunday morning and, after being told he could not stay the night there, opened fire on staff, killing 26-year-old Tiffany Johnson from Minnesota and 24-year-old Philip Crouse from Alaska.

Two others who were injured have been named as Dan Griebenow, 24, who was shot in the neck and remains in a critical but stable condition, and Charlie Blanch, 22, who suffered gunshot wounds to his legs.

Police investigating the shooting are as yet unsure of the motive. Witnesses have described the Arvada gunman as having the appearance of a 20-year-old white male in a dark jacket and skull cap.

Warren added, "The young man - I don't know who he is; I don't think [the victims] knew him - but he must be going through a lot personally in his own life to do something like this."

YWAM International Chairman, Lynn Green, expressed the organisation's sorrow over the killings but said they could take comfort in knowing that those who serve Christ inherit everlasting life.

"Those who lost their lives had dedicated themselves to serve and we feel the sorrow of their absence. Yet we take comfort from the assurance of everlasting life for those who follow Christ in loving service to others," she said.

"It is a great tragedy that our culture seems to produce so many deeply troubled people who express their frustration in violence. We forgive the assailant and we rededicate ourselves to serving young people in the hope that we might bring healing to other needy youth."

Arvada Campus residents, numbering around 80, have been relocated to YWAM's mountain campus near Golden, Colorado, while the police investigation continues.

Warren said they were trying to deal with the situation as best they could.

Police are investigating possible links between the YWAM shooting in Arvada and a separate shooting 12 hours later in a car park outside the New Life Church 65 miles away in Colorado Springs. One person was killed and four others received shot wounds in the incident after a church service.