Josh Strauss and Leone Nakarawa have signed new deals tying them to Glasgow Warriors until 2017.
The two forwards follow Stuart Hogg and Lee Jones in signing two-year extensions with the Warriors, who are third in the Guinness Pro12 and top of their Euroepan Rugby Champions Cup pool.
South Africa-born Strauss, who will be eligible for Scotland from September next year, told the club website: "I've learnt a lot working with the players and coaches at Scotstoun and it was a good decision to move to Glasgow from South Africa.
"I've enjoyed the last three years at the club and I really like the group of players that are here. I'm happy to be staying."
Fiji second row Nakarawa said: "Signing my first professional contract with Glasgow was a big move for me and I'm really enjoying playing for the club and I'm very happy living in the city.
"We have excellent players and coaches at Scotstoun and I believe I can continue to improve working with them. The supporters have been great with me since I joined and I'm delighted to be staying."
Glasgow boss Gregor Townsend said: "Josh and Leone have made a big impact since they joined us and it's a big boost for everyone at the club that they're staying."
Meanwhile, Canada international back Connor Braid has left the Warriors to join London Scottish on a permanent contract until the end of the season.
The 24-year-old had a loan spell with the Championship side earlier in the season.