Uganda's defence minister has warned neighbouring Democratic Republic of Congo of his country's impatience following two recent border attacks.
"This kind of behaviour should not occur in the modern era... We reserve the right to self-defence," state media quotes Amama Mbabazi as saying.
He made the comments in Butogota where three people were shot dead in a cross border raid on Wednesday.
Uganda was one of several countries involved in DR Congo's five-year war.
Last week, DR Congo's soldiers launched a deadly attack across Lake Albert, which divides the two countries.
A British citizen working on an oil exploration barge in Ugandan territory was killed.
As well as condemning the attacks, Mr Mbabazi also lashed out at Congolese authorities for allowing various Ugandan rebel groups to operate on Congolese soil.
"They are living in peace as if DR Congo is nurturing them, giving them not only a home but also the ability to grow in their capacity to cause greater harm to Uganda," he said, Uganda's New Vision newspaper reports.
He said DR Congo was "not interested" in dialogue to resolve security issues along the border.
The minister was also critical of the UN force in DR Congo.
"How can they be in control and let such things happen?"
There are some 17,000 UN troops in DR Congo - the largest peacekeeping force in the world.
Last year's elections were intended to draw a line under years of conflict in DR Congo but parts of the east remain unstable.