A few thousand opposition Cambodia National Rescue Party supporters marched through central Phnom Penh yesterday as the party held its largest public gathering in the capital since protesters were chased out of Freedom Park in early January.

Although Prime Minister Hun Sen suggested in late February that a ban on public assembly in the capital had been lifted, authorities had denied a request from the CNRP to hold a “people’s congress” at Freedom Park yesterday, citing ongoing investigations into clashes at protests on January 2 and 3 that left at least four dead.

The government had, however, granted permission for the party to hold a ceremony at Wat Botum Park to commemorate the 17th anniversary of a grenade attack on an opposition rally at the site that killed at least 16 people and injured more than 100.

With security forces deployed in droves to Freedom Park to thwart any attempt to defy the ban, CNRP leaders decided to hold the congress at their Meanchey district headquarters instead, and following the ceremony at Wat Botum, led a few thousand supporters on a boisterous, hour-long traipse through the city.

Though surrounding streets had been blocked off ahead of the memorial ceremony, police stood idly by as the flag-waving crowds moved down Sothearos and then Norodom Boulevard, over the Kbal Thnal flyover, and down National Road 2 to the party office.

Speaking to supporters who had gathered outside, partially blocking the road, opposition leader Sam Rainsy lambasted the government for blocking access to Freedom Park, or “Democracy Square”, the capital’s

designated protest space.

“We want to change the name of Democracy Square to Dictator’s Square [seeing as] citizens are not allowed to gather there,” he said.

Rainsy also mocked a reported ban instituted in the wake of January’s violence on gatherings of more than nine people, boasting that his party had been able to march unimpeded. Ahead of yesterday, Rainsy had said the events would be “a test” for the government and invited observers “to witness any act of provocation on the part of CPP-controlled forces, whose objective would be to create violence so as to have a pretext to further reduce the democratic space in Cambodia”.

Prominent human rights group Amnesty International on Saturday had called on the government to allow yesterday’s assemblies, and a protest planned by independent broadcaster Mam Sonando for today, to “take place without undue interference and without harassment from security forces”.

General Khieu Sopheak, spokesman at the Interior Ministry, yesterday said that the authorities had “followed the [CNRP] march very closely”.

“We didn’t take any action to stop the march, but [we] just monitored. If they march and if they stand still to occupy any space, action should be taken,” he said.

City Hall spokesman Long Dimanche said the Phnom Penh Municipality considered the march illegal and had received traffic complaints, but that authorities were trying to be “patient”.

“Let people evaluate [how] the opposition party has always made problems.

“I also receive information that there were many people who were unhappy with the way that traffic was blocked,” he said.

Following the “People’s Congress”, which saw supporters take to a stage to air their grievances and explain what course of action they want the CNRP to take, the party released a resolution stating that it would continue to either demand an investigation into election irregularities or an early poll.

Cambodia National Rescue Party leader Sam Rainsy pays his respects to the 1997 grenade attack victims at Phnom Penh’s Wat Botum Park. Pha Lina

It also states that if the National Election Committee is not significantly reformed – a sticking point in negotiations with the ruling Cambodian People’s Party – the CNRP’s boycott of parliament, which began in September, would continue.

In such a case, the CNRP would “continue large scale non-violent demonstrations nationwide”, the resolution says. At Wat Botum yesterday morning, where relatives of those killed in the 1997 grenade attack joined monks and opposition supporters to mourn and honour the dead, Rainsy spoke of alleged interference by Prime Minister Hun Sen at the Khmer Rouge tribunal, the basis for allegations of genocide recently made in an International Criminal Court complaint not linked to the CNRP.

“The Khmer Rouge Tribunal summoned Mr Hor Namhong, deputy prime minister and foreign affairs minister [to the court].

“In [foreign countries], if the judge summons someone and they do not go, he would be jailed. But in our country, they do not think of the court.… He does not go because he has a leader to defend him that says it’s not necessary to go,” he said.

“Another one is named Keat Chhon, the deputy prime minister and former Finance Minister and [adviser to] Pol Pot.… Keat Chhon [was summonsed] but did not go … [because someone above him] told him not to go. [That person] defends criminals, this is a big problem.”

It has been alleged that Namhong was, for a time, in charge of the Boeung Trabek prison under the Khmer Rouge, which he has strongly and repeatedly denied, calling such accusations defamatory.

Chhon worked at the Foreign Affairs Ministry under Democratic Kampuchea, according to witnesses at the Khmer Rouge tribunal.

Rainsy added that 2014 was the “most hopeful year” for Cambodians to find justice, citing the appointment of a new judge to investigate the 1997 grenade attack in a French court.

The CNRP leader and other Cambodians present at the attack have French nationality in addition to Cambodian.

No one has yet been held account for the attack, which saw four grenades thrown at a protest led by Rainsy against a lack of independence and corruption in the judiciary.

Witnesses claimed to have seen the Prime Minister’s Bodyguard Unit, which was deployed to the protest, allowing the grenade-throwers to escape through their lines while blocking pursuers.