(Aram Kirakosyan, PAN Photo via AP). Opposition demonstrators march to protest the former president's shift into the prime minister's seat in Yerevan, Armenia, Friday, April 20, 2018. Beginning last Friday, the protests are against former President Ser...

(Aram Kirakosyan, PAN Photo via AP). Police officers block the path of opposition demonstrators as they protest against the former president's shift into the prime minister's seat in Yerevan, Armenia, Friday, April 20, 2018. Beginning last Friday, the...

(Hrant Khachatryan, PAN Photo via AP). Opposition demonstrators march to protest the former president's shift into the prime minister's seat in Yerevan, Armenia, Friday, April 20, 2018. The protests, which began last Friday, are against former Presiden...

YEREVAN, Armenia (AP) - About 40,000 demonstrators have gathered in Armenia's capital as a week of protests against the country's new prime minister showed no sign of dissipating.

Protesters are calling for the resignation of Prime Minister Serzh Sargsyan, the former president who was appointed this week under a new system that gives the prime minister expanded powers and diminishes the presidency.

The crowd that amassed at a central square on Friday blocked the defense minister's car before police forcefully cleared the way.

The head of the Organization for Security and Cooperation in Europe's human rights bureau called on Armenian authorities to ensure the demonstrations proceed peacefully.

A spokesman for the prime minister, Hovhannes Nikoghosyan, says OSCE isn't in a position "to fully and adequately evaluate the situation" since its Yerevan office closed last year.

40,000 gather in Armenia to demand leader's resignation