Raviraj, 44, was cremated at the Chavakachcheri cemetery while heavily armed security forces kept a low profile along the funeral procession from his ancestral home.
Shops and offices closed in Jaffna, 400 kilometres (250 miles) north of the capital as residents mourned his death and protested Friday's assassination carried out in Colombo, a spokesman for his Tamil National Alliance (TNA) said.
The coffin, draped in the yellow, red and green flag of the TNA, was taken for cremation after Hindu funeral rites.
His family and other mourners were flown in two aircraft to the Palaly military base at the northern edge of Jaffna and later taken to Raviraj's village of Chavakachcheri on Tuesday.
The family wanted the cortege to travel along Jaffna's main road. But the government refused to open land access, shut since August following fighting with Tamil Tiger rebels.
Sri Lankan soldiers carried the coffin and escorted it out of the high security zone of the Palaly military complex before han