"The scale of the problem the government faced in demining can be clearly seen from the number of mines and other devices unearthed and neutralized during the de-mining process," Rajapaksa said.
De-mining is a high risk, time consuming and costly operation which involves skilled manpower and sophisticated equipment.
Most conventional armies have maps and patterns on record which can fast track de-mining but the process gets tedious when mines are indiscriminately laid with no records.
The military says the Tamil Tigers better known as the LTTE were locally manufacturing mines and other improvised devices in small factories deep in the jungles in the former war zone beyond conventional standards with higher amounts of explosives and pellets to maximize the explosion and injuries.Anti Personnel mines that were manufactured by the LTTE during the later stages of the conflict had contained over 100 grammes of C4 explosives as opposed to the conventional ones that carry 40 grammes, the military said.
From 2009 to 2011 a total of 1577 square kilometers or 92 percent of the danger area in the north and east of the country has been cleared and only 124 square kilometers remains, the finance ministry said in its annual report.
Thousands of mines were laid in Sri Lanka's former war zone by the military and the Tamil Tigers where deadly battles raged between the military and the separatist Tamil Tigers.
"It's because of the number of the mines and IEDs laid by the LTTE was so very large that demining in some areas continue to this day," Rajapaksa said.
Officials estimate that 1.3 million land mines are buried in the island's former war zone.