Lord's Resistance Army rebels have killed at least 20 people in the north of Uganda in two separate attacks.
Last year, rebels killed 200 refugees near Lira
A vehicle was ambushed on Thursday night, hours after refugees were hacked to death with the tools they were using to work in the fields, officials say.
The attacks come at a time when aid agencies have expressed concern over increased insecurity close to Gulu.
Despite the attacks, efforts to set up peace talks with the rebel leadership are continuing.
The refugees were killed near Koch Goma camp 25 kilometres south-west of Gulu town.
The rebels "used machetes, axes and hoes that the people were using to dig in their garden to kill them, while those who ran away were shot," said northern Uganda army spokesman Lieutenant Tibaro Kiconco.
He said 16 people had been killed.
About 10 people were taken to Lacor hospital in Gulu town - most of them with head wounds.
Hospital sources report that two of the injured are still in a critical condition - with serious head wounds - the result of blows from axes.
Koch Goma is home to around 18,000 displaced civilians.
The United Nation's World Food Programme says the camp receives food aid on a monthly basis.
However there is not enough food aid for the 1.5m people who have fled their homes in northern Uganda and hunger means some of them till the fields despite the security risk.
Later on Thursday, a vehicle was ambushed by suspected LRA rebels near Kalongo around 70 kilometres south-east of Kitgum town.
An MP from the area said four people had been killed including a soldier.
Lt Kiconco confirmed the ambush took place but did not have casualty figures.
He said the attacks are out of desperation and intended to show that the LRA still exists.
The spokesman said 84 rebels had been killed and 28 rescued in April.
He said one Ugandan army soldier was killed last month.
These reports have not been independently verified.
Former minister Betty Bigombe is still working as a mediator and is in regular contact with the LRA leadership including its leader Joseph Kony whom she hopes to meet soon.
She recently called on Mr Kony to order a cessation of attacks on innocent civilians.
The latest violence will do little to persuade anyone that the message has been sent to the commanders.
The idea of peace talks is fully supported by the UN and influential members of the international community.
Those pushing for talks say the LRA leadership must urgently demonstrate a commitment for peace.