Tottenham have signed Sevilla defender Federico Fazio on a four-year contract.
Ajax say Manchester United have made "no contact at all" over a possible move for Daley Blind.
The QPR manager is desperate to bring in "one or two" new players before Thursday's deadline in the wake of the weekend's FA Cup humiliation at home to MK Dons.
Rangers have already failed with two bids for West Brom striker Peter Odemwingie, and with Ryan Nelsen due to leave for the MLS imminently Redknapp will be a centre-half short as he attempts to steer his side off the bottom of the Premier League.
He said: "When you're in a position like we are, you need to strengthen if you can. I didn't put this squad together, I inherited it."
"I still think we can avoid relegation if I can get the players in that I'm aiming for. We'll give ourselves a real chance if we get them in. I'm sure there'll be clubs looking to do some business but it's always difficult."
"This transfer window, I've never seen anything like it. It's like gang warfare out there."
Redknapp also put up a stout defence of chairman Tony Fernandes, who told his Twitter followers on Sunday he would be "the first to go" if QPR continued to struggle under his leadership.
"Tony Fernandes loves this club," he said. "The club are lucky to have a chairman like him. Nobody is trying harder than him to put things right."