Sri Lanka's police arrested four people and were looking for more suspects on Saturday over the smashing of a Muslim-owned clothing store that raised religious tensions in the country, a spokesman said.
Police Superintendent Buddhika Siriwardena said a search was under way for those who torched and vandalised a section of the three-storeyed clothing store and warehouse on Thursday night in the Papiliyana suburb of Colombo.
Local media video footage showed at least one man in saffron robes, typically worn by Buddhist monks, bringing down a CCTV camera of the store by throwing a stone at it while those in the crowd clapped. The clip was also posted on the website YouTube.
However, there were no monks among those in custody, Siriwardena told AFP, but added that the four men arrested were Buddhists from the majority Sinhalese community.
The owners of the clothing store, which maintains a chain of upmarket shops across the country, said their main warehouse and head office suffered extensive damage in Thursday's "totally unprovoked" attack.
"We sincerely hope there will be no repetition of such violent attacks on innocent civilians and establishments to disturb peaceful co-existence within Sri Lanka," the company said in a statement.
Sri Lanka stepped up security at the weekend after Thursday's violence which the main Muslim political party in the ruling coalition said was a "sequel" to an on-going hate campaign against minority Muslims.
Siriwardena said there had been no fresh reports of unrest from any part of the country and the situation had been quickly brought under control.
The government in a statement on Friday urged people not to be provoked.
The recently formed Buddhist nationalist group, the monk-led Bodu Bala Sena (BBS), or Buddhist Force, denied involvement and said men impersonating monks may have been involved in the attack.
Army units were called in to disperse Thursday's mob, who pelted stones, smashed parked vehicles and torched clothing at the Fashion Bug store. Despite the attack, other retail stores of the chain were open over the weekend.
In January, mobs hurled stones at another Muslim-owned clothing chain near Colombo, while Muslim businessmen have also complained of random stone-throwing, intimidation and calls for boycotts of their shops.
Sri Lankan President Mahinda Rajapakse, who is a Buddhist, urged monks earlier this year not to incite religious hatred and violence.
The United Nations estimates that Sri Lanka's ethnic civil war claimed at least 100,000 lives between 1972 and 2009, when Tamil separatist rebels were crushed in a major military offensive.
Less than 10 percent of Sri Lanka's population of 20 million are Muslim. The majority are Sinhalese Buddhist, while most Tamils are Hindu.