Indonesia issued a tsunami warning Wednesday after an earthquake with a preliminary magnitude of 8.9 hit waters off westernmost Aceh province.

People on Twitter said tremors were felt in Singapore, Thailand, Malaysia and India. High-rise apartments and offices on Malaysia's west coast shook for at least a minute.

The Pacific Tsunami Warning Center in Hawaii said a tsunami watch was in effect for Indonesia, India, Sri Lanka, Australia, Myanmar, Thailand, the Maldives and other Indian Ocean islands, Malaysia, Pakistan, Somalia, Oman, Iran, Bangladesh, Kenya, South Africa and Singapore.

A tsunami watch means there is the potential for a tsunami, not that one is imminent.

The U.S. Geological Survey said the powerful quake was centered 20 miles (33 kilometers) beneath the ocean floor around 308 miles (495 kilometers) from Aceh's provincial capital.

Said, an official at Indonesia's Meteorology and Geophysics Agency who goes by only one name, said a tsunami warning has been issued.

Indonesia straddles a series of fault lines that makes the vast island nation prone to volcanic and seismic activity.

A giant 9.1-magnitude quake off the country on Dec. 26, 2004, triggered a tsunami in the Indian Ocean that killed 230,000 people, nearly three quarter of them in Aceh.

【新闻快讯】据美国地质勘探局网站消息，北京时间2012年4月11日16时38分，北苏门答腊西海岸发生里氏8.9级地震，震源深度33公里。印尼气象与地球物理局官员表示，他们已向28个国家发布海啸警报。

由于印尼位于太平洋地震带和欧亚地震带的交界处，大陆板块在这里交接，地震和火山活动频繁，每年发生的大小地震不下数千次。印尼亚齐省是2004年印度洋海啸的重灾区，海啸夺走了该省近17万人的生命。