Official sources said police deployed special teams to review CCTV camera footage to identify the perpetrators and carry out more arrests.
Police will take stern action against rioters and constables have been issued with orders to use maximum force, Police Chief Chandana Wickramaratne warned in a televised address after rampaging mobs set fire to Muslim-owned shops and vehicles.
The police media spokesman said the illegal activities committed by the persons engaged in violence will be noted in their police certificates.
Police said a curfew would be enforced until further notice in the country's North Western region, and until Tuesday morning in the rest of the nation.
Sri Lanka has been under a state of emergency since a string of bombings at three hotels and three churches killed more than 250 people in mid-April. Militant Buddhist groups have cultivated anti-Muslim sentiment in Sri Lanka for years, sparking fears soon after the Easter bombings that such groups would use the attacks as justification to incite violence against Sri Lankan Muslims.
A Muslim man was hacked to death in Monday's violence in which members of the country's largely Buddhist majority ethnic Sinhalese attacked Muslim-owned shops and homes in several towns, said Rauff Hakeem, a Cabinet minister and leader of the Sri Lanka Muslim Congress.
There was glass everywhere at the Abrar mosque in the Muslim-majority town of Kiniyama that was attacked overnight. "When mobs tried to attack mosques, we fired in the air and used tear gas to disperse them".
In the adjoining Gampaha district, men on motorbikes led arson attacks in the town of Minuwangoda, 45 kilometres (30 miles) north of Colombo, local residents told AFP.
According to the the All Ceylon Jamiyyathul Ulama (ACJU) - the main body of Islamic clerics - there has been increased suspicion of Muslims after the attacks blamed on local Islamic group National Thowheed Jamath, which is believed to have links with the Islamic State (IS) that claimed the carnage. Netblocks confirms that Facebook, WhatsApp, Instagram, YouTube, Viber, Snapchat and Facebook Messenger are blocked on leading internet providers.
Muslims make up almost 10 per cent of Sri Lanka's population of 22 million, which is predominantly Buddhist.
Residents in the town of Kottampitiya recalled how a group of about a dozen people had arrived in taxis and attacked Muslim-owned stores with stones just after midday on Monday, with the mob soon swelling to 200, and then 1,000.
The latest unrest came as Catholic churches resumed their public Sunday masses for the first time since the bombings.