Chelsea have signed Ivory Coast striker David Datro Fofana from Molde and Brazilian midfielder Andrey Santos from Vasco da Gama.
Fofana, 20, joins for a reported £8m-10m on a six-year deal until 2029, with the option to extend it by one year.
Brazil Under-20s international Santos, 18, has joined for a reported £18m.
Chelsea have now made three signings in the January transfer window, following the arrival of France defender Benoit Badiashile for £35m from Monaco.
Fofana scored 24 goals in 65 appearances for Norwegian champions Molde.
“I’m very happy to sign for the club of my dreams,” he said.
Chelsea described the forward, who joined Molde in 2021 from the Ivory Coast’s Amadou Diallo Football Academy, as “a prolific goalscorer and one of European football’s most promising young talents”.
Fofana, who has three caps, recently made his first start for the Ivory Coast.
“The Ivorian’s combination of pace, skill and strength make him a versatile striker, capable of scoring goals but especially adept at holding up the ball and retaining possession under pressure,” added Chelsea.
Santos scored eight goals in 38 appearances for Vasco da Gama.
He made his league debut aged 17 in 2021 before playing a key role in his side’s promotion back to the top flight in Brazil in the 2022 season.
“It’s a very big opportunity for me,” he said. “This is a big club playing in big competitions like the Premier League so I am very excited.
“The players here are so good and I am very happy to be here.”
The Blues are also in talks with Benfica over a move for their Argentina midfielder Enzo Fernandez, 21, who has a £106m release clause.
Graham Potter’s side are 10th in the Premier League after Thursday’s 1-0 loss to Manchester City and have a mounting injury list that includes goalkeeper Edouard Mendy and forward Raheem Sterling.