Violent attacks against Muslims swept the central district of Kandy over the last week.
Tensions remain high across Sri Lanka after the violence broke out following the death of a man from the mainly Buddhist Sinhalese majority last week.
Sri Lanka's Special Task Force soldiers walk past a damaged mosque after a clash between two communities in Digana central district of Kandy.
Police said almost 150 people, including the main instigator, have been arrested over the unrest.
The government declared a state of emergency on Tuesday as the unrest escalated when a Muslim man was found dead in a fire-gutted building.
A total of 146 suspects have been arrested in Kandy - 135 over violence and 11 for violating the curfew - since March 4, a media report said yesterday.
A three-member committee comprising of retired judges will probe whether any violation of law and order is among the reasons for the clashes, evaluate the damages to lives and properties, probe whether there was any conspiratorial hand behind the incidents, Colombo Page reported. "At the same time, the authorities are folding their arms and watching", said Muslim businessman M. Jaffer, as quoted in Thursday's DailyFT newspaper.
"We are investigating who funded them, their future plans, and whether they have any local political leadership and whether there was any foreign involvement behind this", police spokesman Ruwan Gunasekara told reporters in Colombo.
However, three boats belonging to a Muslim businessman outside the district were torched, police said.
Sinhalese and Muslim civil society groups had staged a joint protest in Colombo Thursday calling for tough action against the perpetrators of the riots.
Muslims make up 10 percent of Sri Lanka's 21 million people. Most are Buddhists. Muslims account for 10 per cent of the population.
In an interview with Dawn, Lt. Gen. Senanayake said he had urged President Maithripala Sirisena to "rebuild minds" to ensure the trust of the island's Muslim community in the Sinhala community.
"He expressed concern that many elements of the government's visionary 2015 program seem stalled, despite their importance to sustainable peace, security and prosperity in Sri Lanka", said the statement.