All procurement and accounting officers in Kenya's ministries and state-owned corporations are to leave their offices for fresh screening, an official announced on Monday, as President Uhuru Kenyatta's government grapples with endemic corruption.The officers are to submit personal information including their assets, liabilities and previous record of service by Friday, according to a statement signed by Interior Ministry Spokesperson Mwenda Njoka. He said he does not know how many officers will be affected, but some experts say that more than 500 officials will have to step away from their jobs and submit to new scrutiny."Whereas the exercise is geared toward determining suitability to continue holding public office in the public trust and promote confidence in the public service, the same will be undertaken in a fair and objective manner," the statement said.Kenyatta has been under pressure to curb rampant corruption that has been exposed in several articles in the local press. The government is estimated to have lost hundreds of millions of dollars to corruption according to those reports. Kenyatta said on Saturday that polygraph tests will be used to assess the accounting officers.Outrage has been growing in recent weeks over a number of corruption scandals alleged involving the ministries of health, energy, agriculture, public service and youth. Kenyatta has long been criticised for not acting against corrupt officials despite numerous vows to crack down. The president, who won a disputed second term last year, declared corruption a national security threat in 2015. At the time he pledged to implement the screening of customs and revenue officers, suspected by some in the government of denying the country revenue by taking bribes to overlook tax obligations. That screening has never occurred.In a statement last week 18 Western diplomats urged strong political leadership and zero tolerance for graft.Kenya is considered among the world's most corrupt countries, ranked 143th out of 180 nations by Transparency International in its most recent annual corruption index.But many Kenyan anti-corruption activists have rejected the government actions."It's nonsense. It's a witch hunting exercise to show something is being done to cool down anger," said activist Boniface Mwangi. "There is enough evidence to get people arrested and prosecuted as the auditor general annually has been publishing reports of the theft which show the office of the president leading in diversion of public funds," he said.Mwangi said if Kenyatta wants to fight corruption he should declare his wealth and make it public as Kenyan law requires. He should also make public the wealth of public officials, Mwangi said. In addition Kenyatta should put measures to protect whistleblowers and witnesses because currently those who decide to give information on corruption are at risk. "It's an automatic death sentence," said Mwangi.Mwangi alleged that many who have led corruption have positions in Kenyatta's government."Who is going to vet the thieves? Thieves?," asked Mwangi. "The president is playing for the gallery."* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.