The Montreal Alouettes used the first day of free agency to bolster their secondary, adding four defensive backs over the first two days of free agency.

The Alouettes signed DBs Tommie Campbell, Joe Burnett, and Dominque Ellis Tuesday, and added Mitchell White on Wednesday.

Campbell and White highlight the group. The 30-year-old Campbell, who played the last two seasons with the Calgary Stampeders, is one year removed from being a league All-Star. Campbell finished last year with 37 tackles and two interceptions in 17 games.

White was a division All-Star in 2016 with the Ottawa Redblacks. The 27-year-old spent last season with the Grey Cup champion Toronto Argonauts, finishing with 11 tackles and three interceptions in six games.

Burnett is another division All-Star, having accomplished the feat in 2012 with the Edmonton Eskimos. The 31-year-old played last season with Campbell in Calgary, finishing with 11 tackles and an interception in 11 games.

Ellis spent the past two seasons with the Hamilton Tiger-Cats after starting his CFL career with the Alouettes. The 28-year-old played in five games last year, finishing with 15 tackles and a sack.

The Alouettes also re-signed kicker Boris Bede, defensive back Tevaughn Campbell, and offensive linemen Matt Vonk and Xavier Fulton earlier Tuesday.

Bede, Vonk and Fulton all signed one-year deals while Campbell agreed to a two-year contract.

The six-foot-four, 225-pound Bede returns for a fourth season with Montreal. He made 29-of-35 field goals and 18-of-20 converts last year while averaging a CFL-record 69 yards on kickoffs.

Campbell, a six-foot, 195-pound Toronto native, started nine games last season, registering 13 tackles and one interception, while adding three special-teams tackles. Campbell is currently playing with Canada's national rugby sevens team.

The six-foot-four, 295-pound Vonk, 27, of Burlington, Ont., appeared in nine games last year before suffering a season-ending injury in August.

Fulton, a six-foot-five, 287-pound American. started five games last season with Montreal.