COLOMBO, Sri Lanka (CNN) -- Sri Lanka's government said Monday its forces had killed Tamil rebel chief Velupillai Prabhakaran as he attempted to flee, according to the country's state-run news agency.
The Sri Lankan government says Tamil chief Velupillai Prabhakaran is dead.
The Tamil rebel group, formally known as the Liberation Tigers of Tamil Eelam (LTTE), is aware of the government's report but has yet to confirm Prabhakaran's death or the deaths of its other leaders, according to a posting on the pro-rebel Web site, Tamilnet.com. It said "initial reports indicate a determined massacre by the Sri Lanka Army."
Prabhakaran was one of 19 senior LTTE leaders that the government has identified among the bodies found as its troops completed mop-up operations after routing the Tigers, the defense ministry said.
The leaders include Prabhakaran's eldest son, Charles Anthony, as well as Pottu Amman, LTTE's intelligence leader, according to the ministry.
Prabhakaran founded the rebel group, which has been declared a terrorist organization by 32 countries. It pioneered the use of women in suicide attacks and, according to the FBI, invented the explosive suicide belt.
It was also behind the assassination of two world leaders -- the only terrorist organization to do so. Watch more on the possible end of fighting »
Prabhakaran is accused of masterminding the killing of former Indian Prime Minister Rajiv Gandhi in 1991 in the Tamil-dominated Indian state of Tami Nadu as he campaigned for a second term. Sri Lankan authorities allege that Prabhakaran was avenging Gandhi's decision to send Indian peacekeepers to Sri Lanka.
Two years later a Tigers suicide bomber, allegedly acting under Prabhakaran's orders, detonated explosives that killed Sri Lanka's then-president, Ranasinghe Premadasa, during a rally.
Over the weekend, the militants offered to "silence" their guns after an intense military offensive decimated their ranks, pushed them from their stronghold in the north and east of the country, and cornered the remaining rebels on a small stretch of land.
If the rebels honor their pledge, it would potentially mark the end of the longest-running civil war in Asia.
Prabhakaran's supporters considered him a hero with a single-minded focus -- to fight for the rights of his people. The Sri Lankan government deemed him a war criminal with a disregard for civilian casualties. He was wanted by Interpol on charges including terrorism and organized crime.
In the past it has been reported he wore a cyanide capsule around his neck -- to swallow and kill himself rather than risk capture. And he reportedly expected the same dedication from his troops. As a result, few Tigers have been captured alive.
Sri Lanka's President Mahinda Rajapaksa is expected to announce that "military operations" against the Tiger rebels have ended in an address to parliament and country on Tuesday. Watch aid agencies fear for Sri Lanka »
The rebels have fought for an independent state for minority Tamils in Sri Lanka since July 1983.
Journalist Iqbal Athas contributed to this report.