AID agencies have not yet determined whether the three Spanish aid workers and the Rwandan security guard shot dead over the weekend in Rwanda were deliberately targeted.
The spate of attacks on premises and staff of western nongovernmental organisations (NGOs) in recent days has alarmed the agencies which have withdrawn their staff from Ruhengeri, scene of the weekend attacks, and other parts of northwest Rwanda.
The Minister of State for Development CoOperation, Ms Joan Burton, yesterday expressed her shock at the killings and said she was concerned at their possible impact on the process of reintegration of more than one million Rwandans who have returned from Eastern Zaire and Tanzania in recent months.
The Rwandan government is expected to issue a statement shortly on the safety of expatriate aid workers amid speculation that armed Hutu Interahamwe fighters have begun a campaign to drive such workers out of parts of the country.
Interahamwe fighters, who returned among the refugees from Zaire last November, may want to drive westerners out of the region to allow them to kill witnesses to the 1994 genocide. Alternatively, Interahamwe attacks could result from hostility due to the close working relationship between western NGOs and the Rwandan government.
The circumstances of the weekend attacks and killings remain uncertain, however, and some of them appear to have been at least partly motivated by robbery rather than the desire to kill foreign aid staff.
Representatives of NGOs in Rwanda met in the capital, Kigali, yesterday afternoon to discuss the security situation, but they were not presented with a clear account of the motivation for the attacks.
Up to 30 expatriate development workers from 10 agencies have been evacuated from Ruhengen, where four buildings housing European aid workers were attacked on Saturday and Sunday night.
While some are returning to the town during daylight to assess the situation, none is staying overnight in the town.
The latest attack was on, the Concern house in Ruhengeri on Sunday night, in which two armed men shot dead a local security guard and seriously injured another.
The two expatriate workers based there - one Irish and one British - had a lady been moved to Kigali after attacks in the town the previous night.
There is an unconfirmed report that the armed men asked the unarmed security guards whether there were expatriates in the house before opening fire.
On Saturday night, two groups - each believed to have comprised 10 armed Hutu Interahamwe fighters - attacked three compounds in the town housing the agencies Medecins Sans Frontieres (MSF), Save the Children Fund (SCF) and Medecins du Monde (MDM).
At MSF, where expatriate staff locked the doors and turned out the lights, the men looted the yard before escaping. At SCF, a grenade was thrown into the compound, damaging several cars.
The killings of the Spanish workers took place at MDM. It is now believed that the armed gang had taken various items, including passports, from the house and were on their way out of the gate when they were challenged by Rwandan army soldiers. They retreated back into the house and in the shooting that followed, the three Spaniards and three Rwandan soldiers were killed.
An American aid worker was shot in the knee and has since had his leg amputated.
The two Concern workers evacuated to Kigali will not move back to Ruhengeri until the security situation has been clarified, according to Concern's overseas director, Mr Howard Dalzell. Concern's country director in Rwanda, Mr Dominic McSorley, will travel to Ruhengeri today to assess the situation.
In the meantime, according to Mr Dalzell, Concern's projects - which include a centre for unaccompanied children and programmes to help returned exiles - will continue to be operated by local staff.
Trocaire has moved its seven expatriate workers in north west Rwanda as well as two based in Goma, eastern Zaire, to Kigali pending more information on the situation.
According to Trocaire's emergencies officer, Mr Niall Toibin, there have been several attacks on foreign aid workers in recent weeks in an area of Gisenyi, where Trocaire staff have been carrying out food distribution.
Another Irish NGO, Refugee Trust, has two Irish workers based in Kigali, a considerable distance from the scene of the weekend attacks.