Tehran , Iran ( CNN ) -- Iranians marked a holiday that leads up to the Persian new year under the watchful eyes of police Tuesday night after the Islamic republic 's supreme leader tried to discourage the celebrations . Thousands of people turned out , some in groups as large as 400 people , to dance , listen to music and light bonfires in side streets around Tehran on the festival of Chaharshanbe Soori . But unlike other holidays in recent months , there was no immediate sign that the observance was becoming a platform for protests against the country 's leadership . Parties continued into early Wednesday , including one in the northern neighborhood of Zafaranieh where about 150 people danced to music pouring out of cars in the neighborhood . Some revelers played cat-and-mouse games with police who roamed the streets , looking to break up ongoing celebrations . Watch YouTube video of men dancing around a fire . Ayatollah Ali Khamenei , the country 's supreme leader , had urged Iranians to ignore Chaharshanbe Soori , an ancient festival held on the eve of the last Wednesday before spring . It dates back thousands of years and leads up to Norooz , the holiday that begins with the first day of spring and the Persian new year , which falls on Saturday this year . Watch YouTube video of people throwing fireworks in Tehran . In a statement published by Iranian news sites , Khamenei said the festivities have no basis in Islam , and can cause `` harm and corruption . '' `` It is appropriate to avoid it , '' he said . Watch YouTube video of revelers in Tehran shouting `` death to the dictator '' Iran has been wracked by anti-government demonstrations since the disputed June 12 presidential vote that resulted in the re-election of hardline President Mahmoud Ahmadinejad . The government has beefed up security to ensure `` order and calm '' during the two-week period celebrating Norooz , stationing 200,000 security personnel across the country , according to Ahmadinejad 's official news site . Tuesday 's celebrations were closely monitored by police in Tehran , with officers randomly stopping and searching cars around Mohseni Square and other major streets and plazas . Are you in Iran ? Send photos , videos of the protests . In one case , brief clashes broke out late Tuesday between revelers and plainclothed members of the Basij , the pro-government paramilitary militia , who chased them away with batons and stun guns . And in one eastern Tehran neighborhood , security forces spray-painted passing cars from which motorists were tossing firecrackers . Police at checkpoints around the city were looking for the marked vehicles . A video posted on YouTube showed what the poster said was an anti-government protest in another Tehran neighborhood , where protesters could be heard chanting `` Death to the dictator . '' Earlier in the week , the chief prosecutor in the eastern city of Mashad warned that those who engaged in `` disruptive behavior '' during Chaharshanbe Soori would face `` strong consequences . '' It 's a precaution that 's become increasingly commonplace in Iran , especially in advance of holidays , as the government continues to warn against political demonstrations that have emerged since last summer 's disputed presidential elections . The Iranian government quashed anti-government protests that brewed in February as the nation commemorated the 31st anniversary of the Islamic Revolution , which marked the end of the country 's Western-backed monarchy and the start of an Islamic republic . In the days that led up to the February 11 holiday , the government mobilized security forces and heightened its warnings , saying it would arrest protesters and hold them until the end of Norooz , on April 9 . Six protesters who were arrested in December on the Muslim holiday of Ashura were sentenced to death on Monday , the day before Chaharshanbe Soori , the semi-official Fars News Agency reported Monday . Their sentences are being reviewed by an appeals court , Fars said . Another 86 people were found guilty Tuesday of acts against the Islamic republic , Iran 's semi-official Fars News Agency reported . The Revolution and Public Court of Tehran said most of the defendants were given prison sentences . Meanwhile , around 350 inmates at Evin prison have gone on a hunger strike to demand that their cases be examined before Norooz , saying their ward is so overcrowded with recent political arrestees that prisoners are in poor health , according to the Committee of Human Rights Reporters , an Iranian group . Eyewitnesses in Iran said thousands of riot police and security officers lined the streets of the capital , Tehran , and patrolled major intersections on motorcycles and on foot Monday night . Beginning Saturday , police also have set up checkpoints along major roads in Tehran , and vehicles have been stopped and searched from late at night into the early morning hours , witnesses said . CNN 's Reza Sayah contributed to this report .
Groups of Iranians danced , listened to music and lit bonfires to celebrate holiday . Country 's supreme leader Ayatollah Ali Khamenei had urged Iranians to ignore occasion . Chaharshanbe Soori celebrated before Persian new year . No immediate sign that celebrations would turn in to platform for protests .