Championship side Blackpool have signed Saer Sene, David Ferguson, Connor Oliver and Alex Henshall, and agreed a deal to keep defender Darren O'Dea.
Forward Sene, 28, signs a six-month contract after his release by Major League Soccer side New York Red Bulls.
Defender Ferguson and midfielder Oliver, 20, have signed 18-month deals having been on trial from Sunderland, while Ipswich winger Alex Henshall, 20, has agreed a one-month loan deal.
O'Dea, 27, joined the club in December.
The Republic of Ireland international was released by Ukrainian side Metalurh Donetsk last August and has also played for Celtic, Reading, Ipswich, Leeds and Toronto.
Left-back Ferguson spent time on loan at Darlington in 2012, while Oliver had a stint at League Two side Hartlepool last year.
The deals came a day after midfielder Jamie O'Hara committed himself to the club and Grant Hall arrived on loan.
Meanwhile, Blackpool owner Owen Oyston has written an open letter to fans in the Blackpool Gazette in response to allegations from the Blackpool Supporters Trust about the way he runs the club.
Oyston revealed he is taking legal action against Tim Fielding, who has now resigned from his position as Supporters Trust chairman.