An explosion that struck one of the most prestigious hotels in Myanmar's main city was caused by a small, homemade time bomb, police said Tuesday.
Police officer Myint Htwe said three suspects have been detained in relation to the blast, which went off just before midnight Monday at the Traders Hotel in Yangon, ripping apart a guest's room and wounding one American. It was one in a series of unexplained blasts to hit the country in recent days.
The hotel blast was followed by two small explosions before dawn Tuesday in the Mandalay region, police said, adding that there were no reports of injuries.
The blast at the 22-story Trader's Hotel, located in the heart of the country's commercial capital, blew out a window in the guest's 9th floor room, shooting shards of thick glass more than 30 meters (yards) into the street, but there were no other visible signs of damage to the exterior of the building.
The device apparently went off in the guest's bathroom, scattering towels, toiletries and a red purse across the entrance way floor. A chair was overturned and part of the wooden wardrobe lifted off its hinges and lying on the ground.
A 43-year-old American woman was slightly injured and taken to a Yangon hospital, police and hotel staff said. Her husband and their two children, aged 5 and 7, were unhurt.
"Our consular officers in Rangoon (Yangon) have visited the U.S. citizen and are providing appropriate consular assistance," said Sarah Hutchison, the U.S. Embassy press officer, refusing further comment due to privacy considerations.
A dozen police and heavily armed soldiers with a sniffer dog entered the glitzy hotel soon after the explosion. Later, many of them crowded into the destroyed room, blocked off with yellow security tape, to inspect the damage.
Others carrying assault rifles and wearing bullet proof vests strolled through the main lobby.
Traders' general manager Phillip Couvaras said in a statement that the hotel, part of the Shangri-La group, was working with authorities to investigate what happened.
But "because this is an active police investigation we cannot comment further at this time," he said. "The safety of our guests and staff are our highest priority and we are obviously monitoring the situation."
Small explosions occurred frequently when Myanmar was under 50 years of military rule, most often blamed on anti-government student activists or armed ethnic insurgent groups. But such incidents have become rare in recent years.
The country has undergone rapid change since 2011, when the former army junta ceded power to a quasi-civilian government led by retired military officers. Since then, President Thein Sein has embarked upon a series of major reforms, liberalizing the economy and the political sphere, easing censorship and freeing political prisoners.
But many activists and rights groups have complained that country is still far from free, and dissent is frequently stifled. Thein Sein's government has also struggled both to end a civil war with ethnic Kachin rebels in the north, and curb a rising wave of anti-Muslim violence that has killed hundreds of minority Muslims and displaced nearly 150,000 more in the predominantly Buddhist country since last year.
No one claimed responsibility for the recent blasts, which came as the country prepares to take over the chairmanship of the Association of Southeast Asian Nations. It will also host the Southeast Asian games in December, considered a showcase event by the government.
Unidentified assailants have planted several homemade bombs in and around Yangon in recent days, reportedly killing two people and injuring three others.
The first bomb reportedly went off Friday at a guesthouse in Taungoo, a town 200 kilometers (125 miles) from Yangon, according to the independent media outlet, the Democratic Voice of Burma. It said two people were killed, but those casualties could not immediately be confirmed.
On Sunday, two other homemade bombs went off in Yangon. One of the bombs, attached to the bottom of a truck parked outside a market on Yangon's eastern side, wounded three civilians, according to a statement posted on Myanmar's police Facebook page.
Another homemade bomb exploded one at a bus stop in the west of the city, but no casualties were reported in that blast, police said.
The explosions Tuesday occurred at 3 a.m. and 5 a.m. in Sagain, in Mandalay region. No further details were available.
Police called on the public to be vigilant and report any suspicious packages found at bus or train stations, or at the seaport.
Associated Press writers Aye Aye Win, Esther Htusan and Todd Pitman contributed to this report.