Tanzanian authorities have arrested dozens of people ahead of planned anti-government protests, intensifying a crackdown on dissent as activists demand democratic reforms and the release of jailed opposition leader Tundu Lissu amid heightened security across the country.

According to Mr Misime, investigations have uncovered alleged efforts to incite violence through social media platforms and online discussion groups.

Heavy security has been deployed across Tanzania's commercial capital, Dar es Salaam, ahead of planned anti-government demonstrations, as fears grow of a repeat of last year's…