A bomb attached to a motorcycle in a hotel parking lot exploded Saturday in southern Thailand (search), injuring about 30 people, according to police and hospital workers.

Three of those hurt were in serious condition after the blast in Sungai Kolok (search), a town on the border with Malaysia, said police Capt. Pibul Wattanatham.

The bomb exploded at about 7:30 p.m. in the parking lot of the Marina Hotel (search), injuring patrons at the Top Ten bar and coffee shop, said Pibul.

Most of those hurt were Malaysian tourists, according to a worker at the local hospital.

Three southern Thailand provinces are the only ones with Muslim majorities in Buddhist-dominated Thailand. Officials have blamed the violence on Muslim separatists, although no groups have taken responsibility for it.

Thai Muslims have long complained of discrimination in jobs and education by the central government. They also say their culture and language are being suppressed.

A decades-old separatist movement in the south was contained in the late 1980s, but violence began to resurface two years ago.