Bangladesh continued to struggle on their tour of the Caribbean as they ended the second day of the second and final Test against West Indies trailing by 276 runs with just three first innings wickets remaining.
Resuming on 246 for three, West Indies were bowled out for 380, an hour after lunch.
Shivnarine Chanderpaul was unbeaten on 84 for West Indies after Al-Amin Hossain earned reward for some fine seam bowling as he finished with 3-80.
But Roach was quickly among the wickets, removing the top three in the Bangladesh batting order for 62 runs, with Tamim Iqbal the only one to get started with his 48.
Jerome Taylor claimed the wicket of Mominul Haque thanks to a brilliant diving catch at short leg by Jermaine Blackwood.
Skipper Mushfiqur Rahim, who has held together Bangladesh's batting on the tour, was bowled by Taylor for four as the tourists found themselves at 68 for five.
Roach then removed Nasir Hossain and Taijul Islam as the tourists closed on 104 for seven and face a long haul to save the Test.
Image: Kemar Roach of the West Indies
Photograph: Gareth Copley/Getty Images