Dec 21, 2006
Fifteen girls kidnapped at the same time were released on Tuesday. The Tigers admitted that taking the children was a "serious mistake".
One of the boys is reported as saying the rebels had threatened to kill them if they refused to go with them.
The Tigers said they had taken action against those involved in the incident.
"The remaining seven boys have been released and they have reached their homes," their headmaster, Saravanamuthu Peethambaram, told the BBC Tamil service.
"I met them a short time ago."
When news of the abductions emerged on Tuesday, rebel military spokesman Rasaiah Ilanthirayan initially told the BBC Sinhala service that the junior Tigers who abducted the children had been expelled from the movement.
"It was a mistake by the field commanders, but we are taking strict disciplinary action against our own people involved in this."
In a statement issued later on Tuesday, Mr Ilanthirayan said that the teenaged pupils wanted to join the rebel movement and had come of their own volition to Tiger-held areas.
The statement said that when it was discovered they were underage, they were told to return home.
But one of the boys has now given a contradictory account to the Reuters news agency.
"They had grenades in their hands and threatened us: 'If you don't come with us, we'll explode these grenades'.
"We pleaded with them, saying we were students and wanted to sit our O-level exams."
He said the boys and girls were driven away from a private tutorial centre in the eastern Ampara area where they had been studying for examinations. They were then forced to walk 10 km (6 miles) to a rebel camp, the boy said.
About 100 students from the same school have been boycotting their exams, demanding the immediate release of their fellow students.
Correspondents say it is a rare display of open protest by Tamil civilians against the rebels.
A regional officer for the International Red Cross, Martin de Boer said, "This was a clean-cut abduction," Reuters reports.
He also said that a breakaway faction of the rebels led by Col Karuna, now fighting the main Tamil Tiger movement is now carrying out as many kidnappings at the Tigers.
Last month, the United Nations children's agency, Unicef, said that "elements in the Sri Lankan military" were helping Col Karuna to abduct children to fight the Tamil Tigers - an accusation flatly denied by the government.
Later on Thursday, police said at least 19 civilians, 16 men and three women, were abducted by unidentified gunmen in the eastern Batticaloa district.
They were travelling by bus to the capital, Colombo, at the time. It is not clear who was responsible. The Tigers said they had "no connection with this incident"
This year has seen a sharp increase in violence in Sri Lanka, with at least 3,400 people dead, the authorities say.
The BBC's Roland Buerk in Colombo says that all sides are believed to be building up their forces, preparing for a possible return to full scale war.
The Tamil Tigers have been fighting for independence for the 2.5m-strong minority Tamil community in the north and east of the country.