Police officers in Sudan have denied allegations linking them to a New Year's Eve attack on 800 Christians at Khartoum's Anglican cathedral, the church priest has said.

Canon Sylvester Thomas of All Saints Cathedral has told Compass Direct that officers fired tear gas into the church claiming they were trying to apprehend a man involved in a stabbing.

The church staff registered a case with local police on January 2, but officials have not established who carried out the attack that caused US$7,000 damage, Thomas said.

Thomas said, "The police were trying to claim, 'This group doesn't belong to us and we don't know where they came from. But they were all in uniform and using guns and [police] cars."

A police spokesman in Khartoum refused to comment on the attack when contacted by Compass.

Sudanese Vice President Salva Kiir, a southern Christian, publicly called for the church attackers to be punished yesterday in Juba. Kiir's comments came in a nationally televised speech when he and northern President Omar Al-Bashir met to commemorate the second anniversary of a peace deal that ended the nation's 21-year civil war between northern Islamists and southern Christians.

During the ceremony, broadcast live on Sudan TV, Kiir and Bashir criticised each other openly for blocking implementation of the peace agreement and the sharing of oil revenues.

In the letter to the governor of Khartoum, Bishop Kondo noted that members of the cathedral had felt threatened by police cars parked outside all day prior to the attack. "Most of the officers were of high rank," the letter said.

Police first fired 10 canisters of tear gas into and around the cathedral 20 minutes after the midnight service had begun, Thomas told Compass. The congregation panicked and began to stampede out the front door of the church, only to be met by officers who beat them with whips and sticks.

Among those present were United Nations workers and government officials, including Vice President Kiir's secretary as well as former Vice President Abel Alier.

"The second assault of tear gas fell just in front of [Alier] and he was almost suffocated," Thomas said. "His wife had to carry him near the tap and pour water on him, and that is how he survived."

An officer told Thomas that they had not been firing on the church but had been trying to apprehend a group of men fighting in the street, one of whom had been stabbed. The police claimed they opened fire on the group after the men began throwing rocks to resist arrest.

Church staff investigated police claims that a man named Stephen Chol, from Hag-Yousif in Khartoum North, had been stabbed. But the telephone number provided by police turned out to belong to someone else, and no hospital in the area had any record of a patient treated for stabbing, Thomas said.