The mysterious generosity that has fed Salvation Army red kettles in the form of new $100 bills has re-emerged this Christmas season in the Twin Cities.

"St. Grand," as the anonymous donor is known, slipped $1,100 each into two kettles Friday in Roseville, one drop at a Lunds & Byerlys on County Road C and the other at Cub Foods on Larpenteur Avenue, according to the Salvation Army. The scenario repeated itself Saturday: same amounts, same locations. For the math-impaired, that's $4,400.

These gestures, whether by one clandestine donor or more than one, mark the fifth consecutive year of the C-note contributions to the charity's annual Red Kettle Campaign.

"We are so excited that St. Grand is back and blessing us again with these donations," said Maj. Jeff Strickler, the Salvation Army's Twin Cities commander. "This person quietly makes the most generous donations, without any recognition, and we appreciate it so much."

In 2014, St. Grand made a splash with a $10,000 donation in a kettle at a Lunds in Bloomington, and then followed up with seven $1,000 gifts throughout the season.

Charity officials have been stumped ever since the mystery donations began in 2011.

The Salvation Army has set an ambitious Christmas fundraising goal this season of $11.6 million. As of Saturday, the charity had raised about $1.6 million, compared to $2.1 million at this time last year.

The charity is seeking bell-ringer volunteers to sign up for one of 575 kettle locations online at salvationarmynorth.org. The average kettle brings in $30 an hour, the organization says.

The Twin Cities Salvation Army is one of the largest providers of Christmas toys in the metro area, providing gifts for roughly 15,000 children. The charity also serves 1,200 hot meals every day, shelters nearly 900 people each night and provides groceries for more than 100,000 people annually.