Eleven Tamil National Alliance councillors wore black shawls, saying they were remembering the LTTE cadres who died in 2009 when Sri Lankan troops defeated the Tamil Tigers.
Council Chairman Ariyawathi Galappaththi did not allow the members to go ahead with the remembrance, saying it was not listed in the agenda.
Members of the ruling party objected to any attempt to commemorate Velupillai Prabhakaran who they called a deadly terrorist. Prabhakaran was the chief of the LTTE, who was killed by Sri Lankan troops in 2009.
Eastern province, a multi-ethnic region consists of each of the three communities -- Sinhalese, Tamils and Muslims.
More From This Section
The separatist LTTE called the East a part of the Tamil homeland.
The conflict has claimed at least 100,000 lives, about 40,000 of them in the final months of fighting, according to a UN estimate.
Sri Lanka in late March banned groups and individuals who live overseas and help the LTTE to regroup.