Vitrox bomb

Group Marshal Nathan and Turner were members of the Tenth Sontaran Battle Brigade who plotted to destroy the Doctor's TARDIS with a vitrox bomb. There, the two Sontarans encountered the Sixth Doctor, Tegan Jovanka and Gareth Jenkins and recognised Gareth as the Earth Defence Force leader who would defeat them in 2001. They were killed by Gareth when he pressed a button on the TARDIS control console and shot pressured steam at the Sontarans. (NOTVALID: A Fix with Sontarans)