Burma's military rulers have said ethnic Karen rebels are responsible for a bomb that killed at least seven people, state-run media have said.
The bomb exploded on Wednesday in a market in Karen state, near the border with Thailand, where lunar Karen new year celebrations were taking place.
State-controlled newspapers said rebels from the Karen National Union planted the bomb but gave no other details.
There has been no independent confirmation of the government's claim.
The government often blames ethnic minority groups or dissidents for bombings such as this - accusations which are denied by the groups concerned.
Failed ceasefire attempts?
The KNU has been fighting for greater autonomy for six decades.
The bomb went off in the town of Phapun, about 200km (120 miles) north-east of Burma's main city, Rangoon.
The KNU is one of a number of minority groups which have been fighting the central government since Burma's independence from British colonial rule in 1948.
Many of these have reached ceasefire agreements with the government recently, but talks with the KNU have so far failed.
Burma's junta is said to be putting pressure on the ethnic rebel groups to join the government's "border guard forces" ahead of next year's polls.
Burma is scheduled to hold elections in 2010, but critics say there is little chance they will be free and fair.