The man, who entered the building at 9:45 pm local time, is reported to still be in the building which is surrounded by police.
Reports say that one woman and one man are dead, and that the woman, who was a supervisor at the home, had managed to phone police before she was killed by the attacker's knife.
More than 60 monks who worked in missions in Africa live at this retirement residence for monks and priests.
The motive for the attack is still unknown.
to storm - to suddenly enter
masked - covering the face
armed - carrying a weapon (gun)
retirement - the time in life when a person stops working because they are old
to take hostage - to force someone to stay with you and not let them leave
mission - a religious trip to another place meant to help people and teach them about that religion
motive - reason for doing something