Sri Lanka is marking a holiday on Wednesday to celebrate the defeat of Tamil Tiger rebels.
"The government has also asked all state institutions to fly the national flag for one week," an official said.
However state security forces said that they were on a state of high alert against revenge attacks from any remaining rebels.
On Tuesday pictures of the body of the man who is believed to be rebel leader Velupillai Prabhakaran were released.
The BBC's Charles Haviland in Colombo says that officially the holiday has been called as a mark of respect to troops who have defeated the Tamil Tigers.
There are still some delighted youths rushing into the roads waving the red, yellow, green and saffron national flag, our correspondent says, but with businesses firmly shut and stormy monsoon weather descending on the city, the streets are much quieter than they were.
The state English-language daily has the word "triumph" in huge blue letters on its front page, but Rajiva Wijesinha, one of the government's regular spokesmen, writes that he is glad that "vulgar triumphalism" has not broken out.
Mr Wijesinha wrote there was a need to plan for the future and bear in mind Tamil suffering.
The US, the UN and China - a key and growing ally of Sri Lanka - have all urged ethnic reconciliation on the island, with Washington calling for "new power sharing arrangements".
'Best of cowards'
The government has said that renegade Tamil Tiger leader Vinayagamoorthi Muralitharan, also known as Colonel Karuna, has positvely identified Mr Prabhakaran's body.
Col Karuna defected from the rebels in 2004 and is now a government minister.
The defence ministry website has also released more details of Mr Prabhakaran's death. It said that he was found with no cyanide capsule, but with his identity card and the dog tag.
"He was certainly not man enough to fight a single battle against army, but instead tried to save his life until the last moment," it said.
"Not for a single second did he he want to commit suicide, but tried to escape betraying his most loyal followers before a soldier shot him down.
"We are not going to comment on how he died... simply, he was the best of the cowards."
The ministry said that Mr Prabhakaran's body was found on Tuesday morning, contradicting earlier reports that it was discovered on Monday.
The army also says it has found the body of one of the last rebel leaders still unaccounted for. It said that the bullet-riddled head of the rebels' Sea Tiger wing, Soosai, was found by troops in marshy land on Tuesday evening.
"Our motherland has been completely liberated from separatist terrorism," President Rajapaksa told jubilant lawmakers in a nationally televised victory speech to parliament on Tuesday.
The president reached out to the mainly Hindu Tamil community - comprising about 20 million people - pledging that everyone in Sri Lanka should be able to live "in safety without fear and suspicion".
"All should live with equal rights. That is my aim," he said, briefly speaking in the Tamil language.
The president said that he would negotiate some form of power-sharing deal following the war and stressed the need for an agreement.
"We must find a homegrown solution to this conflict. That solution should be acceptable to all the communities," he said.
Our correspondent says that it is expected the government will devolve more power to the provinces giving Tamils more political say in some parts of the island.
Tamil politicians have said the government must address the causes of the long-running conflict.
The pro-rebel TamilNet website has not commented on reports of Mr Prabhakaran's death since it denied he was dead on Tuesday - before the release of photos depicting his body.
The Tigers had been fighting for a separate state for Tamils in the north and east of Sri Lanka since the 1970s.
About 80,000 people have been killed in the conflict and thousands displaced.