COLOMBO, Sri Lanka - Sri Lanka's former war zone is again seeing unexplained killings, abductions and rapes despite tight security in the region, lawmakers said Thursday.

A group of ethnic Tamil lawmakers submitted to Parliament a list of 15 serious incidents that they say occurred in the northern Jaffna peninsula in the past two months. They asked the government to explain how such crimes could take place considering the area's security situation.

The area is the cultural heartland of ethnic Tamils and was a stronghold of Tamil Tiger rebels before their 26 year campaign for an independent state was put down by the military in 2009. About 50,000 government troops have been stationed on the peninsula since.

The list submitted to Parliament included five killings, four suspected killings, three abductions and three incidents of rape.

"These things are happening under a heavy security blanket. How could they happen without the government knowing?" said Suresh Premachandran, one of the lawmakers.

Police spokesman Prishantha Jayakody said the situation was not as bad as the lawmakers depicted.

"We have received just two complaints of killings and we have arrested the suspects in one of those cases. There is no major problem," he said.

Killings, abductions and threats were common during the civil war, though both the rebels and government were known to exaggerate claims for their own benefit or to make their opponent look bad.