Five armed Palestinian groups joined Hamas in the deadly 7 October attack on Israel after training together in military-style exercises from 2020 onwards, BBC News analysis shows.he groups carried out joint drills in Gaza which closely resembled the tactics used during the deadly assault – including at a site less than 1km (0.6 miles) from the barrier with Israel – and posted them on social media. They practised hostage-taking, raiding compounds and breaching Israel’s defences during these exercises, the last of which was held just 25 days before the attack.BBC Arabic and BBC Verify have collated evidence which shows how Hamas brought together Gaza’s factions to hone their combat methods – and ultimately execute a raid into Israel which has plunged the region into war. By Abdelali Ragad, Richard Irvine-Brown, Benedict Garman and Sean Seddon. Full Text-> BBCnews