Matthew Smith is co-founder and CEO of Fortify Rights. Follow him on Twitter @matthewfsmith. The opinions expressed here are solely his.

(CNN) Four years ago, I was in Myanmar's Rakhine State soon after deadly violence erupted between ethnic Rakhine Buddhists and stateless Rohingya Muslims. It was a horrendous scene. And it's happening again.

Back then, Buddhist civilians and state security forces unleashed coordinated attacks against Rohingya and other Muslims. I documented pre-dawn raids and cold-blooded massacres.

In a small village in Mrauk-U Township on October 23, 2012, 70 Rohingya were killed, including 28 children -- 13 under the age of 5. Children were hacked to death. Some were thrown into fires.

Entire villages were razed; smoke billowed from homes and mosques in 13 of 17 townships statewide and bodies were disposed in mass graves, none of which have been exhumed for forensic purposes. I personally documented four separate mass gravesites.

At the time, an unpublished United Nations investigation obtained by Al Jazeera's investigative unit, found more than 100 Rohingya women and girls were raped. The authorities then corralled more than 130,000 Rohingya into more than 40 squalid interment camps, where they remain confined today.

This all happened under former President Thein Sein, a longtime military general lauded by the West as a reformer.

Now Nobel-laureate Aung San Suu Kyi is State Counselor, the de facto head of state --and the same atrocities are happening again.

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The recent violence

On October 9, a group of Rohingya men and boys allegedly attacked three police outposts in Maungdaw and Rathedaung townships, killing nine police. This was highly unusual. Despite unending persecution, Rohingya militancy hasn't been seen for decades.

The Myanmar military commenced a full-on offensive that's ongoing in northern Rakhine State -- a veritable black zone sealed off from aid workers and international observers.

We've documented unlawful killings of unarmed Rohingya men , and we've steadily received allegations of mass rape of Rohingya women and girls by army soldiers.

Meantime, the civilian government and military continue to block all access to affected areas. Pre-existing aid programs, which were keeping thousands of Rohingya alive, have been suspended for eight weeks.

According to the UN, the authorities are denying at least 130,000 men, women and children access to humanitarian aid -- food, nutrition and health care. Thirty thousand are likely displaced in the blackout zone. An estimated 3,000 children suffer from severe acute malnutrition.

Without urgent aid, they will likely die.

Nearly all of the international aid workers in Maungdaw Township have left as the government has not renewed their travel authorizations. Independent monitors and media are still barred.

State-run media has claimed international journalists and human rights groups are working "hand in glove" with terrorists. It has alluded to Rohingya a s a "thorn" that "has to be removed," and as "detestable human fleas."

Make no mistake: this is genocide talk. And it is happening with Aung San Suu Kyi's imprimatur.

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Suu Kyi's culpability

The dominant narrative suggests Suu Kyi's hands are tied and that she has no control over the military. This is a half-truth.

By law, the military controls the ministries of Defense, Home Affairs and Border Affairs. These are instrumental ministries with respect to abuses in northern Rakhine State and Suu Kyi doesn't control them.

But in military lockstep, the State Counselor's office has flatly denied any abuses may have taken place since October 9. And she's since doubled down, accusing the international community of "always drumming up cause for bigger fires of resentment.

Her office has demanded apologies from the BBC and the UN's refugee agency after the latter alleged "ethnic cleansing" was taking place.

Moreover, Suu Kyi does control the ministries of Information, Foreign Affairs and others, and she could swiftly renew travel authorizations for aid workers. But she isn't.

No one in the country has as much moral authority to change public opinion and counteract hate speech as Suu Kyi.

So UN officials and governments are rightly sounding alarms.

The UN Special Advisor on genocide prevention last week called for urgent action while the office of the UN High Commissioner for Human Rights alleged again that crimes against humanity may be taking place. The US government called for a "credible and independent investigation," a call echoed by various Asian parliaments in recent weeks.

But this is not enough.

Left to its own devices, Myanmar will continue to destroy this ethnic and religious minority. We can't let that happen.

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What can be done

In his final days in office, UN Secretary General Ban Ki Moon should travel to Myanmar and personally ensure the authorities provide immediate and unfettered access to all populations in need in Rakhine State. Any failure to end this despicable aid blockade will result in significant loss of life -- indeed, it likely already has.

In addition, UN member states should push for a UN Commission of Inquiry into what is happening in Rakhine State.

In August, Aung San Suu Kyi appointed an "Advisory Commission" on Rakhine State, which is led by former UN Secretary General Kofi Annan. Fortify Rights welcomed the move, but Annan himself has said the commission does not intend to focus on human rights. It's unclear if that directive comes from him or the State Counselor, but regardless, for the Rohingya, it's a problem.

Annan is expected to address the press this afternoon following a three-day guided tour of Rakhine State. We don't expect him to address ongoing human rights violations, but he should. At this point, it's a moral imperative.

His commission isn't the only one expected to abandon human rights. Last week, Suu Kyi's government appointed yet another body to look into the situation in Rakhine State since since October 9. It has all the markings of a whitewash -- it's led by retired army general Myint Swe, a man formerly blacklisted by the US government -- and doesn't include a single Muslim commissioner.

Now is the time for independent UN-mandated Commission of Inquiry to address the totality of the human rights situation in Rakhine State, including grievances from the Rakhine Buddhist communities.

Such an investigation would provide much-needed credibility and could cooperate with Kofi Annan's team while also delving deep to establish the facts, identify perpetrators and make recommendations to end, once and for all, the cycle of atrocity crimes against Rohingya -- before it's too late.

Aung San Suu Kyi appears to be watching a possible genocide unfold. The international community must not.