YANGON, Myanmar ? Three explosions rocked Myanmar’s capital on Saturday, killing 11 people and wounding 162 others in the latest bombings blamed on ethnic rebels in the military-ruled country.

The blasts occurred in rapid succession at a convention center and two bustling supermarkets in neighborhoods across the city of 5 million people starting around mid-afternoon. It was not immediately known how many people died at each site.

State television said several ethnic rebel groups, including the Karen National Union and the Shan State Army, were behind the attacks. It called the perpetrators “terrorists” who were trying to disrupt “stability and tranquility.”

A public advisory urged Yangon residents to remain alert for further violence.

Authorities shut down markets across Yangon over security concerns after the blasts, which came less than two weeks after a purported rebel bombing at a market in the northern city of Mandalay that killed two women and wounded 15 other people.

The first bomb on Saturday blew up at an exhibition hall where a Thai trade fair was under way, killing three people from Myanmar, including a Buddhist monk, and wounding many others, a security official said on condition of anonymity.

Myanmar officials are often reluctant to speak on the record for fear of being reprimanded by the country’s secretive military regime.

The second explosion tore through a City Mart supermarket in northern Yangon, wounding several people and wrecking the store’s exterior. Soldiers moved in to guard the area while smoke poured out of the ground-floor supermarket.

The final explosion struck northwestern Yangon’s Dagon shopping center at about 3 p.m., wounding many people.

“I heard a loud explosion and saw several sales girls in their gray and light yellow uniforms rushing out of the City Mart with blood streaming down from their faces,” said Hla Hla, a 32-year-old resident who arrived there minutes after the blast.

The military has ruled Myanmar, also known as Burma, since 1962. The current regime took power in 1988 after brutally crushing a pro-democracy uprising. It keeps tight control over the population and anti-government violence is unusual, often bringing severe punishment.