Sudan on Friday denounced Western criticism of the arrest of two high-profile former officials opposed to military rule and charged with corruption, saying it was contrary to "diplomatic norms and practices".

Khalid Omer Yousif and Wagdi Salih were arrested on Wednesday, a move Norway, the United States, Britain, the European Union, Canada, and Switzerland condemned as "harassment and intimidation" by Sudan's military authorities.

"This is blatant interference in internal Sudanese affairs, contrary to diplomatic norms and practices," the Sudanese Foreign Ministry said in a statement.

Both men had been part of the government that was toppled on October 25 and had been detained in the weeks following. Since then, military leaders have repeatedly warned of foreign interference.

The two had been involved in a taskforce that seized assets from members of ousted President Omar al-Bashir's regime that has come under criticism from the military. A committee reviewing its work said on Sunday it had found irregularities.

"The two citizens referred to were in fact detained based on clear criminal suspicion, not as a result of any political charge or motive, and the ambassadors concerned should have taken care to obtain accurate information from official sources," the foreign ministry statement said.

The coup ended a partnership between the military and civilian political parties, drawing international condemnation and plunging Sudan into turmoil, with frequent nationwide demonstrations against the coup and a wave of political detentions.

Lawyers told Reuters this week more than 100 people remain in prison, while some 2 000 had been arrested and released.

Protests organised by neighbourhood resistance committees have drawn hundreds of thousands of people, and at least 79 have been killed and more than 2 000 injured in crackdowns.