England goalkeeper Tom Heaton has committed his future to Burnley by signing a new contract until June 2018.
Wolfsburg have moved to sway Newcastle away from a move for Bas Dost by claiming the striker would command a fee around the £29million mark.
The 21-year-old Cameroonian has been training with Rovers for the past month and has signed a two-year deal after impressing in pre-season friendlies against Wrexham and Portimonense.
Songo'o, who is the younger brother of former Sheffield Wednesday loanee Franck, started his career in Spain before moving to MLS side Sporting Kansas City, where he was released from this summer.
Rovers boss Gary Bowyer has made strengthening his back line a major priority and adds Songo'o to a defensive pool including fellow new signings Tommy Spurr, Matt Kilgallon and Todd Kane.