Sudan's President Omar al-Bashir on Wednesday said deadly protests over fuel-price increases last month were part of an effort to topple his regime.

"After we announced the latest economic measures they said this is a chance to overthrow Ingaz," he said in a reference to his government which took power in a 1989 Islamist-backed coup.

"They brought agents, thieves and hijackers, and they said Khartoum will be overthrown," he said in eastern Sudan, without specifying exactly who "they" are.

"But Khartoum could not be overthrown because it was guarded by God," he said in a speech broadcast live on national radio.

Bashir has previously spoken of "conspiracies" linked to the demonstrations and his Interior Minister Ibrahim Mahmoud Hamed claimed foreign links to "criminal" acts which allegedly occurred during the protests.

On September 23 the government cut petrol subsidies, driving up pump prices by more than 60 percent and sending thousands into the streets to protest in the worst urban unrest of Bashir's 24 years in power.

Rights groups say around 200 people were killed by security forces.

Authorities have now upgraded their toll, reporting 60-70 deaths, and said they had to intervene when crowds turned violent, attacking petrol stations and police.

A wide range of observers say the protests -- accompanied by calls for the downfall of the regime -- were a spontaneous reaction by citizens, many of them poverty-stricken, who have endured two years of rising prices since South Sudan separated with most of Sudan's oil production.

Observers have said the protests point to an urgent need for reform by a regime grappling with wars, dissension within its own ranks, economic crisis and international isolation.

Bashir said the government plans a major economic conference next month as part of efforts to stabilise the economy.

"We will bring experts to provide a solution to the problems and to plan programmes," he said.