Advocates warned that the Azerbaijani offensive against Nagorno-Karabakh could represent only the beginning of a renewed, genocidal aggression against the Armenian people.
The four are in isolation while their contacts are being traced. They join three other Vatican residents who tested positive in recent weeks.
Since 1988 Armenia and Azerbaijan have had an undeclared war over the territory of Nagorno-Karabakh, which lies inside Azerbaijan, but has an ethnic Armenian majority.
The powerful head of the Vatican's saint-making office, Cardinal Angelo Becciu, resigned Thursday from the post and renounced his rights as a cardinal amid a financial scandal that has reportedly implicated him indirectly.