Bangkok, Thailand (CNN) -- Tens of thousands of demonstrators slept on the streets of Bangkok on Monday night, continuing a protest intended to force Thailand's Prime Minister from office, authorities said. The protesters have laid siege to major intersections in Thailand's large and hectic capital city. At their peak on Monday evening, they numbered as many as 170,000, Lt. Gen. Paradon Pattanathabut, the nation's security chief, said Tuesday. But many of the demonstrators have since returned to their homes in the Bangkok area, Paradon said. About 60,000 of them stayed out on the streets overnight, he said, sleeping under tents and mosquito nets.
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NEW: About 60,000 protesters stayed out on the streets of Bangkok overnight
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NEW: At their peak Monday, they numbered as many as 170,000, authorities say
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They have laid siege to major intersections in the Thai capital
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The protesters are demanding that Prime Minister Yingluck Shinawatra step down
His supporters, known as "red shirts," plan to hold demonstrations in various places in @placeholder, but not the capital or south of the country, on Sunday.