BANGKOK (AP) — Tens of thousands of anti-government protesters marched through the streets of Thailand’s capital Saturday, reviving their whistle-blowing, traffic-blocking campaign to try to force the resignation of the country’s prime minister.

The protest came after a lull in anti-government rallies and amid growing concern of violence between opponents and supporters of embattled Prime Minister Yingluck Shinawatra. It also came a day before a key vote to elect a new Senate.