Unidentified miscreants on Sunday night lobbed a petrol bomb at the residence of Meghalaya Chief Minister Conrad K Sangma, police said.

The incident took place around 10.15 pm when vehicle-borne attackers lobbed two Molotov cocktail bottles at the premises of his personal residence at Third Mile in Upper Shillong, they said.

No one was injured in the incident, according to a senior district police officer.

The first bottle was lobbed at the front part of the house while the second one was thrown behind the backyard, he said, prompting the guards there to douse the fire immediately.

Curfew was imposed in Shillong and mobile internet stopped in at least four districts of Meghalaya on Sunday amid vandalism and arson over the police encounter of a top militant leader, who had surrendered, officials said.

The curfew was imposed in Shillong from 8 pm on Sunday till 5 am on Tuesday, they said.

Mobile internet was stopped for 48 hours, beginning at 6 pm, in East Khasi Hills, West Khasi Hills, South West Khasi Hills and Ri-Bhoi districts, they said.

Stray incidents of vandalism and arson were reported, having the potential to disturb public peace and tranquility and cause a threat to public safety, Home Secretary CVD Diengdoh said, quoting reports from the police headquarters.

Violence was reported from these areas as Cheristerfield Thangkhiew, a militant who had surrendered, was laid to rest at a cemetery in Shillong after being killed by police in an encounter at his home on August 13.

Thangkhiew was suspected to be the mastermind of a spate of IED attacks since his surrender in 2018, police said.

Director-General of Police R Chandranathan said there was ample evidence against Thangkhiew when he sent his team to arrest the "retired" general-secretary of the banned Hynniewtrep National Liberation Council (HNLC).

Thangkhiew allegedly attacked the police with a knife when his home was being raided, provoking a retaliatory shot in which he was killed, Chandranathan had said.

Hundreds of his supporters carried black flags as his body was taken to the cemetery.

Government vehicles were vandalised and a police vehicle was set on fire at Jaiaw area of Shillong allegedly by his supporters, police said.

Banning mobile internet, the chief secretary said, "Messaging systems like SMS, Whatsapp and social media platforms like Facebook, Twitter and Youtube are likely to be used for transmission of pictures, videos and text and have the potential to cause serious breakdown of law and order."

The curfew was imposed in Shillong through an order issued by East Khasi Hills district administrator Isawanda Laloo.

The Meghalaya Human Right Commission has also taken suo moto cognisance of the encounter, noting, "The instant case appears to have resulted in gross human rights violation which according to Article 21 of the Constitution mandates for protection of life and personal liberty for every person within the territory of India."

The commission has directed the chief secretary to submit a detailed report on the incident within 15 days, failing which the commission has said it will conduct its own investigation into the matter.