A convent of the Teresian Carmelites in Ambernath, near Bombay, was invaded by a group of assailants who desecrated a cross and left threatening messages behind.
On Monday, the day after the attack, Dolphy D'Souza, vice president of the All India Catholic Union, and a spokesman for the Bombay Catholic Sabha, condemned the incident in a statement published by the country's episcopal conference.
Some of the scrawled messages said: "Run away, we will come back"; "Go away, this country is ours"; "Now it is the cross, next time it will be your heads."
The convent's superior, identified only as Sister Diana, told SAR News that the attack marked the first time the women religious had been threatened.
"We do not know who the criminals are except that they claimed to belong to a Hindu group," she added. "We are not scared as we have dedicated our lives to the service of the poor and needy."
The woman religious added that the police have promised to patrol at night to prevent further incidents.
The Teresian Carmelites run three homes for the elderly in Bombay. They set up the fourth one in Ambernath in 2001.