Sri Lanka on Wednesday reiterated that there was no threat to the country's national security despite allegations by the opposition that the Tamil Tiger rebels maybe try to regroup.

Opposition parliamentarian and former president's son, Namal Rajapakse, on Wednesday tweeted that the recovery of a suicide jacket and explosives from a house in the former war-torn north earlier in the day raised questions if the Tamil Tiger rebels were trying to regroup in the island nation.

However, Defence Secretary Karunasena Hettiarachchi told Xinhua that the recovery was "nothing extraordinary" as such explosives and ammunition were hidden by the rebels during the war period.

"We recover various kind of ammunition very often as these were all hidden by the LTTE during the war. So the question of our national security being threatened does not arise," Hettiarachchi said.

In addition to the suicide jacket, police also discovered a stock of explosives and bullets which were hidden in a house in Chawakachcheri, in the north.

Police had reportedly raided the house on a tip-off that the owner had in his possession drugs and marijuana and the suspect had fled the area during the raid.

The opposition has called on the government to take responsibility for the "breakdown in security" and take control of the escalating crime rate.

Sri Lankan forces defeated the Tamil Tiger rebels in May 2009, ending a 30-year civil conflict.

The island's north remained the stronghold of the rebels before they were militarily defeated.

(Xinhua)