Gunfire and explosions rocked Bangkok following clashes between pro-government "red shirts" and protesters, leading to fears of further violence as Thais head to the polls.

Witnesses near the ballot distribution centre in Lak Si, in the north of the capital, described a chaotic scene in which explosions and sporadic gunfire lasting an hour echoed through the air, forcing people to seek shelter in a nearby shopping centre.

The BBC reported that as many as six people, including one journalist, may have been injured in the clashes, although it was unclear whether the injured were pro- or anti-government demonstrators.

The violence took place in a suburban stronghold of the ruling Puea Thai party, after anti-government demonstrators blocking the delivery of ballot boxes to the Lak Si district office clashed with hundreds of government supporters wielding batons and metal bars.

Various photographs and video footage of the clashes showed unidentified gunmen in flak jackets firing rifles and handguns and bystanders and journalists huddled together in an army checkpoint. The Thai Election Commission has since decided to suspend voting in the area in order to avoid further violence, local media reported.

The clashes are the latest round of violence in three months of anti-government protests that have seen at least 10 people killed and more than 570 injured, with demonstrators calling for the ousting of the prime minister, Yingluck Shinawatra, whose government they claim is corrupt and should be replaced by an unelected "people's council".

Yingluck's Puea Thai party is largely expected to win the snap polls, a major blow to the main opposition Democrat party, which supports the anti-government protests and is boycotting the election. Protesters have vowed to stop voters from heading to the booths and obstructed a number of ballot boxes from being delivered both in Bangkok and 12 provinces in the south, the election commission said.

Protesters last week prevented some 2 million people across Thailand from casting advance votes last Sunday by chaining shut polling stations, blockading roads, and, in some circumstances, forcibly removing voters from the polling areas.

Although some 130,000 police and 10,000 soldiers have been deployed across Thailand for election, tension and unease have begun to permeate the capital, where most of the recent violence – from drive-by shootings to grenade attacks – has taken place.

In Thailand's often colour-coded world of political rivalry, pro-government "red shirts" generally clash with anti-government "yellow shirts".

But protest leaders encouraged their followers to wear red in celebration of the Chinese new year, and some present at the clashes – including unidentified men firing guns – could be seen wearing green armbands, the same colour as those issued by the Thai Journalists Association, potentially putting members of the media in danger through association.

Led by the former MP Suthep Thaugsuban, protesters have set up ad hoc camping sites at rally stages across the capital, taken over government ministries and even threatened to take Yingluck hostage in their bid to rid Thailand of the "Thaksin regime", a reference to Yingluck's billionaire brother and former prime minister, Thaksin Shinawatra, who was ousted in a military coup in 2006 and now lives in Dubai to avoid corruption charges that he claims were politically motivated.

Saturday's The violence is yet another chapter in an ongoing, years-long battle between those who support Thaksin, a former telecoms tycoon who won voting support from northern and northeastern provinces for his populist policies such as universal healthcare and rice-subsidy schemes, and those who believe him to be nothing more than a corrupt businessman who sullied Thailand's politics.

Critics point to Thaksin's populist agenda, including the rice-subsidy scheme that has cost Thailand roughly $1bn and left a number of farmers without payment, and an amnesty bill that would have allowed Thaksin to return to the country without being imprisoned, as proof of the "dirty politics" that his party engages in.

Much of the continuing battle has been painted as a simple north versus south, rich versus poor, divide, in which the mainly urban Bangkok elite and southern states are competing for power against the mainly rural north and north-east voters who support Thaksin.

But a growing dissatisfaction with the government's handling of various policies, including the rice-subsidy plan, has seen protesters include many groups, with demonstrations taking place even in red shirt strongholds in northern provinces, where farmers' networks have blockaded roads and vowed to boycott the vote in order to voice their dissatisfaction with Yingluck's government. "The government took our rice and never paid us," said Kittisak Rattanawaraha, who leads the Northern Farmers Network in Pichit, where pro-Thaksin forces have long set politics. "We've been airing our grievances for months, but the government hasn't paid serious attention to our plight – so we will not be voting on Sunday."

Various other groups – including academics, businessmen and politicians – also claim their frustration with the government, claiming that they have been embarrassed by Thaksin's "greed" for money – and, by default, his sister's stance as a so-called puppet in her brother's party, whose slogan reads "Thaksin thinks; Puea Thai does".

"I really hoped he could bring a new way of governing to Thailand, but he is a human buyer – he buys everyone," says Kaewsan Athibodhi, leader of the Thai Spring group and an outspoken Thaksin opponent who investigated the former prime minister for corruption as part of a committee.

"Our culture, our way of thinking right now in Thai culture, is not 'democracy'. Our culture is patron and client, and authoritarian. We accept power and we need patrons, but we need to go under democracy. We have no choice. It is the best choice for us to live together, whether we have a clever or foolish leader."

Critics of the protest leader Suthep Thaugsuban, a former deputy prime minister who came to power after Thaksin was ousted in the 2006 military coup and has faced corruption charges of his own, allege that those attempting to "reform" Thailand are just as dirty as Thaksin, and may be suffering from an inability to win popular support.

The opposition Democrat party has not won an election in 20 years and protesters insist that reform must occur before elections take place, although how they intend to initiate those reforms is still unclear.

In a nation that has seen 18 attempted or real coups since 1932, the threat of yet another one in the coming days or weeks – whether by the military or the judiciary, both of which have forced Thai governments from power in the past – seems ever present, with one study projecting a 10.9% likelihood of a coup occurring this year.

So far Thaksin, the man the protesters love to hate, has remained silent on the violence currently racking his country. But his lawyer and spokesman, Noppadon Pattama, said that the former prime minister was "worried about the future of Thailand".

"He is worried about the destruction of the democratic system in Thailand," Noppadon explained. "People here do not play by the rules, that's the problem."

As for the ill-conceived midnight amnesty bill that would have allowed Thaksin to be reunited with his billions and avoid imprisonment – which sparked the protests and has caused death and injury – Noppadon sits back and clasps his hands together. "Looking back, it wasn't a good idea. It was an unfortunate move and it provided our opponents with lots of ammunition against us," he concedes, sighing. "It was a miscalculation."