As reported by the Daily Nation, Tuwei has guaranteed the delegation maximum security and insisted that its scheduled meetings with Kenyan officials will go ahead as planned.

"I'd like to assure all that security in all aspects has been taken care of and the meetings will take place," he said.

"There shouldn't be any panic."

Tuwei was speaking in the aftermath of the terrorist attack on Riverside Drive, an upmarket neighbourhood of Nairobi, on Tuesday (January 15).

Kenyan authorities have said today that nine people have been arrested in connection with the attack which saw gunmen open fire. 

Yesterday, the police announced that the death toll from the siege at the DusitD2 hotel and business complex had increased from 14 to 21.

Six more bodies were found at the scene and police said an officer had died of his injuries.

Fourteen people are still missing, according to the Red Cross.

Somalia-based Islamist group Al-Shabaab said it was behind the attack.

The 14-strong IAAF delegation that arrived in batches on Monday (January 14) and Tuesday (January 15) includes head of event operations Toni Jorba, executive director of communications Jackie Brock-Doyle and chief information officer An Dang Duy.

Technical delegates Gemma Castano and Imre Matrahaz are also present along with platforms and distribution operations manager Frederick Sanchez, executive producer for productions Mark Fulton and head of competition management Luis Saladie.

The delegation will hold meetings with sports cabinet secretary Rashid Echesa, principal secretary Kirimi Kaberia and Athletics Kenya executives, led by Tuwei.

"This visit is extremely important for Kenya and will effectively kick off an extremely important leg of our preparations to host yet another successful global competition," Tuwei was reported as saying by the Daily Nation.

In a statement sent to insidethegames, the IAAF said it is in regular communication with its team on the ground and the feedback it has is that "all has gone smoothly".

"The stadium and our accommodation was on the other side of Nairobi from Tuesday’s attack and there has been extra security at all hotels across the city," the statement adds.

Nairobi was awarded the 2020 IAAF World Under-20 Championships in July of last year. 

The candidacy of the Kenyan capital was formally endorsed by the IAAF Council during the first day of a meeting in Buenos Aires.

The decision to award Nairobi the biennial event followed a successful IAAF World Under-18 Championships there in 2017.

Crowds of up to 60,000 attended the Championships at the Moi International Sports Centre.

On the eve of the 2017 World Under-18 Championships, Kenya's then Sports Minister Hassan Wario thanked IAAF President Sebastian Coe for having the "confidence" in the country to stage the event. 

Wario's comments came amid fears of escalating violence across Kenya prior to the country's Presidential elections in August 2017.

Security fears in Nairobi forced a number of countries, including the United States, Australia, Great Britain, Switzerland, New Zealand and Canada, to withdraw from the Under-18 Championships.

Al-Shabaab also issued public threats to Kenya as a result of their military intervention in Somalia.

Back in 2013, the group killed 67 people at Nairobi's Westgate Shopping Mall.

Those involved in a shooting at Garissa University College in 2015, where almost 150 people lost their lives, also claimed to be representing Al-Shabaab.