KYIV, Ukraine (AP) — Several hundred retirees took to the streets of the Belarusian capital Monday to demand the ouster of President Alexander Lukashenko, Belarus' authoritarian leader who won his sixth term in office in a widely disputed election.

The demonstrators gathered on one of the central squares of Minsk, chanting “Go away!” and “Lukashenko, retire!” The square was cordoned off by security forces and several of the rallygoers were detained, according to the Viasna human rights center.

Mass protests erupted in Belarus, an ex-Soviet nation of 9.5 million, after official results from the Aug. 9 presidential election gave Lukashenko a landslide victory over his popular opponent, Sviatlana Tsikhanouskaya. She and her supporters refused to recognize the result, saying the vote was riddled with fraud.

Thousands of people have since regularly rallied in Minsk and other cities, demanding Lukashenko's resignation and a new vote. Some of the Sunday demonstrations drew up to 200,000 people.

The largest and the most sustained wave of protests posed a major challenge to Lukashenko, who has run the country with an iron fist for 26 years, relentlessly stifling dissent.

Authorities have cracked down hard on the largely peaceful demonstrations. Police used stun grenades, tear gas and truncheons to disperse the rallies. Thousands have been detained and scores brutally beaten.

A total of four people are reported to have died since the protests began in August as the result of the crackdown on demonstrators and opposition supporters.