A Roman Catholic priest has been killed and several nuns injured in attacks in northern Uganda believed to have been carried out by a rebel group. The attacks have alarmed the Catholic community in the east African country.

The Roman Catholic archbishop of the northern Ugandan town of Gulu, John-Baptist Odama, said he believes Tuesday's killing of a Catholic priest and the attack on a group of nuns on Wednesday near Gulu is linked to a threat made against the Catholic Church by the a group identified as the Lord's Resistance Army.

Roman Catholic leaders said that last week, the leader of the LRA, Joseph Kony, told his fighters to destroy Catholic missions, kill priests and missionaries, and beat up nuns.

Archbishop Odama said he is investigating the circumstances of the attacks, but he did not rule out the possibility that the latest violence might be linked to that threat. He said he does not understand why the LRA is targeting the Catholic Church.

"I'm only wondering why, suddenly, it has switched and changed into a religious war targeting specifically the Catholic Church and particularly the leaders of the Catholic Church, like the priests, the religious nuns," he said. "This to me has been a puzzle. Up to now, I have failed to understand."

The LRA has waged a civil war in northern Uganda for the past 16 years. Its leader, Joseph Kony, is a self-styled prophet, who once claimed he wanted to form a society based on the biblical Ten Commandments - but his motives for fighting remain unclear.

There has been increased rebel activity in the north. The head of an Italian mission group working in northern Uganda said his priests have reported seeing many guns, grenades and even new uniforms circulating around the north. Church leaders say they believe the influx of arms and other materials accounts for the increased violence in the area.

On Tuesday, a group of religious leaders accused the Sudanese government of supporting the LRA. Some have accused Sudan of supporting the LRA because Uganda allegedly supports the Sudan People's Liberation Army, the rebel movement fighting against the Sudan government. Sudanese officials have denied supporting the LRA.