YANGON, Myanmar (CNN) -- An explosion rattled Myanmar's main city, Yangon, on Thursday morning, the eve of the one-year anniversary of a junta crackdown on anti-government protesters, police said.
A bomb, placed by a fence at a downtown park near City Hall, injured seven people, police said.
The military regime has tightened security and has been carrying out patrols in and around Yangon throughout the week amid rumors of another uprising this year.
As many as 110 people were believed to have been killed last year when security forces clashed with thousands of protesters led by Buddhist monks on September 26. The dead included 40 monks.
The protesters were among many involved in ongoing demonstrations against the country's military regime.
Witnesses said the violent crackdown came as hundreds of monks defied a military ban on public assembly.
Until then, demonstrations led by the monks -- who are highly respected in the predominantly Buddhist country -- had gone largely unchallenged by the military, which has ruled the country since the 1960s.
The protests were sparked by a huge fuel price increase imposed by the military government, and quickly escalated. It was informally dubbed the "Saffron Revolution" because of the maroon robes with saffron sashes that the monks wore.
Myanmar's military junta said in mid-October that it had detained more than 2,900 people during the crackdown.
On Wednesday, United Nations Secretary-General Ban Ki-moon applauded the release of several political prisoners, including the nation's longest-serving political prisoner, U Win Tin. Watch U Win Tin after being released »