Suspected Filipino rebels seized a Chinese tourist and a hotel receptionist from a resort in eastern Malaysia, then fled on the speed boat they arrived in, Malaysian and Philippine officials have said.
Six men armed with pistols raided the Singamata Reef Resort on Wednesday night, according to local media reports. The Chinese tourist was said to be a woman from Shanghai in her late 20s, while the receptionist was a 40-year-old Philippine national.
The Singamata is a mid-range resort popular with Chinese tourists in the Semporna district of the on Borneo island. It has cottages on stilts over the water.
China urged Malaysian police to rescue its citizen and ensure safety, saying it would "follow this incident closely".
"We sent relevant staff to the site and ask the local police to make an all-out rescue effort while ensuring the security of Chinese citizens and taking effective measures to safeguard the security of Chinese tourists," Foreign Ministry spokesman Hong Lei told reporters.
Malaysia Prime Minister Najib Razak said the attack could be an attempt to stir up more trouble between China and Malaysia.
China's ties with Malaysia have come under stress recently because of anger among Chinese over the search for the missing Malaysia Airlines jetliner, which was carrying 153 Chinese nationals.
Kidnappings for ransom
The attackers were believed to be from the Abu Sayyaf, a Filipino rebel group that has been implicated in seaborne kidnappings for ransom in the region before, a Philippine intelligence official told the Associated Press.
A spokesperson for the Philippines military told Al Jazeera that that it was not yet known whether the abducted had been brought to the southern Philippines, but they were monitoring the area.
Al Jazeera's Jamela Alindogan, reporting from the Philippines, said the spokesperson told her the abduction had been conducted in a manner similar to Abu Sayyaf's previous kidnappings.
"They believe it is possible they may have stopped in one of the islands in the Philippines between Tawi-tawi and Sulu," she said.
The abductions underscore the persistent security threats in Borneo's Sabah state, a popular tourist destination and dive spot that is a short boat ride from the southern Philippines, which has long been home to Muslim rebels and criminal gangs.
Last November, suspected Abu Sayyaf fighters shot and killed a Taiwanese tourist and kidnapped his wife from a resort in the Semporna area. The woman was released a month later in the southern Philippines. Authorities did not say whether a ransom was paid.
The Abu Sayyaf has tenuous historical links to international armed groups, including al-Qaeda, but a US-assisted Philippine military crackdown on the group's heartland in Sulu province in the southern Philippines has weakened it considerably in recent years.
The group has around 300 fighters and is focused on kidnappings for ransom, and is believed to be holding more than a dozen captives, including two European bird watchers who were seized from Tawi-Tawi province in 2012, according to the Associated Press.
In 2000, Abu Sayyaf gunmen crossed the porous maritime border with Malaysia in speedboats and snatched 21 European and Middle Eastern tourists, and Malaysian and Filipino workers from Malaysia's Sipadan diving resort and brought them to the southern Philippines, where the captives were released in exchange for ransom.
Malaysian authorities, worried that the kidnappings have tarnished the country's image as a tourist destination, have beefed up security and patrols along the sea border.