The blast damaged the army vehicle and vehicle carrying aid workers belonging to Caritas Organisation, a non-governmental organisation, the government said.
The explosion occurred as Sri Lanka's international donors were urging the Liberation Tigers of Tamil Eelam (LTTE) to attend the April 19-21 talks in Geneva aimed at salvaging a fragile Norwegian-brokered truce.
"The LTTE has continued to blatantly violate the ceasefire and the commitments made in Geneva by conducting planned operations against the security forces, in many instances in total disregard for civilians in the vicinity," Anusha Pelpita, Director of Government Information said in a statement.
However, despite many such assurances, the LTTE has shown scant regard to such undertakings, he said.
"This is another example