Sri Lanka is celebrating a national holiday Wednesday to mark the military defeat of the Tamil Tiger rebels and the end of the nation's 26-year-long civil war.

Despite the festive atmosphere, security forces remain on high alert, concerned about the possibility of revenge attacks.

Sri Lanka's military says government troops shot and killed eight Tamil rebels in the east Wednesday.  Pockets of rebels are presumed to have survived the military campaign that ended this week.

The international community is welcoming the cessation of fighting and urging the Colombo government to begin reconciliation efforts.

United Nations Secretary-General Ban Ki-moon said he will visit Sri Lanka this week to see firsthand the damage done by the conflict.  

The U.N. estimates 280,000 people have been displaced by fighting the last several months.

Aid groups are complaining that their access to government-run displacement camps has been further restricted in recent days.  

The U.N. refugee agency has called on the Sri Lankan government to allocate more land for construction of emergency shelter, water and sanitation facilities.  

That agency and the International Committee of the Red Cross are also demanding access to civilians in areas where fighting has taken place.

Some information for this report was provided by AFP and AP.