Watford have signed Belgian striker Obbi Oulare, Algerian midfielder Adlene Guedioura and Colombian forward Victor Ibarbo on a season-long loan.
Oulare, 19, arrives for an undisclosed fee on a five-year deal while Ibarbo, 25, joins from Cagliari.
Guedioura, 29, arrives from Crystal Palace on a three-year contract after previous loan spells at the Hornets.
Watford's Matej Vydra and Miguel Layun have joined Reading and Porto respectively on season-long loan deals.
Porto have the option of making Mexico international Layun's move permanent for a fee of £4.4m next summer.
|Fan's view: Matt Rowson, writer for BHaPPY blog|
|"The final day of the transfer window saw the Hornets make two permanent and one loan signing, whilst three of last season's promoted side departed on loan.|
|"The first of these saw Mexican utility man Miguel Layun join Porto early this morning; that this feels like an awfully long time ago is the consequence of a frantic deadline day thoroughly in keeping with a summer that has seen 15 players signed, 13 depart and well over 100 linked.|
|"The popular return of Adlene Guedioura has offset some of the disappointment in players not retained; most Watford supporters will now welcome a dark, quiet room to lay down in for a bit."|
The 27-year-old joined the Hornets from Granada in January and helped them achieve promotion to the Premier League last season. He has made four appearances this season, scoring one goal.
After joining the Portuguese Primeira Liga leaders, he said: "I've definitely reached my full maturity."
Vydra, 23, who signed a permanent deal at Watford over the summer, scored 16 times from 31 league starts to help the Hornets to promotion during a loan spell from Udinese.
He will reunite with Reading boss Steve Clarke, who managed the striker during a loan spell at West Brom during the 2013-14 season.
Defender Gabriele Angella, 26, has also left Watford on loan, joining QPR for the rest of the season.
Ibarbo, who has spent the last seven months on loan at Roma, is a Colombian international and helped his country reach the quarter-finals of the 2014 World Cup.
Oulare scored nine goals in 39 appearances for Club Brugge and featured as a substitute in the Belgian side's recent Champions League play-off tie with Manchester United.
Find all the latest football transfers on our dedicated page.
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