C4 and RPG datamined in the client
Datamainer, known in the community under the PlayerIGN nickname, found references to C4 explosives in the game files, which is different from Sticky Bomb, added to PUBG in 6.1 update. In particular, PlayerIGN found the C4 icon...
...as well as an animation to activate the explosives:
Video for C4 arming animations while proned and standing— PlayerIGN (@PlayerIgn) February 16, 2020
(different from sticky bomb) pic.twitter.com/n09ANbe2jH
Also, he found in the client of PlayerUnknown's Battlegrounds the sounds of C4 and grenade launcher "Panzerfaust", which the developers showed in the trailer to the patch 6.1 and promised to add to the game later: