North Korea is marking the second anniversary of the death of leader Kim Jong-il, days after the dramatic purge of a top-level official.
Images from Pyongyang showed ranks of thousands of officials at a ceremony to commemorate Mr Kim.
His son, Kim Jong-un, inherited the leadership after his death in 2011.
Last week he presided over the execution of Chang Song-thaek, his uncle and a powerful figure seen by outside observers as his mentor.
Mr Chang was accused of multiple crimes, state media said, including forming a power base and attempting to overthrow the state.
On Monday, UN Secretary-General Ban Kim-moon described his execution as “very dramatic and surprising”.
He urged regional nations “while they must be vigilantly and carefully watching the development of situation, not to take any premature actions”.
Residents laid flowers at monuments to both Kim Jong-il and his father, Kim Il-sung, North Korea’s first leader.
Kim Jong-il, who ruled North Korea for almost two decades, died on 17 December 2011.
On Tuesday, his third son and chosen successor Kim Jong-un attended a ceremony to remember his father.
The young leader wore a sombre expression, the BBC’s Lucy Williamson reports from Seoul.
She says the ceremony, in a large hall, was as much about the current leader as the old one.
Kim Jong-un sat on the podium flanked by North Korea’s ceremonial head of state, Kim Yong-nam, and the head of the army.
“All our people and soldiers have struggled and achieved victory for the past two years by holding our great leader [Kim Jong-il] in high esteem,” Kim Yong-nam said in his speech.
On Monday thousands of North Korean soldiers lined up in front of the state mausoleum to pledge their allegiance to Kim Jong-un.
The South Korean president, meanwhile, held a meeting of top security officials, warning of possible “provocations” from North Korea in the wake of the purge of Mr Chang and his aides.
His sudden fall from grace and rapid execution have sparked fears of instability inside North Korea.
Mr Chang, who was married to the elder Mr Kim’s sister, was thought to have facilitated the transfer of power from father to son two years ago.
It was also widely believed that he was highly influential behind the scenes.