Singapore will hold a snap general election on September 11, officials said Tuesday as Prime Minister Lee Hsien Loong seeks a new mandate from voters worried over immigration and the high cost of living.

Despite a slowing economy the People’s Action Party (PAP), which has ruled for more than 50 years thanks to strict political controls and Singaporeans' rising affluence, is expected to keep its overwhelming majority in parliament against a fragmented opposition.

Singapore and Indonesia on Tuesday agreed to step up cooperation against the Islamic State (IS) amid fears that militants returning from the Middle East could mount attacks in Southeast Asia.

"We are both worried about ISIS and we both have nationals from our countries involved in these terrorist activities including in the Middle East," Singapore Prime Minister Lee Hsien Loong said after talks with visiting Indonesian President Joko Widodo.

The death toll following a strong earthquake that jolted Malaysia's Mount Kinabalu last week has risen to 18 after the final two remaining victims who were unaccounted for were confirmed dead on Wednesday.

The remains of Navdeep Singh Jaryal, a Singaporean student and Mohammad Ghazi Mohamed, a Singaporean teacher, will be sent to their home country after further forensic tests in Malaysia, according to a statement from Singapore's education ministry.

Boulders "the size of cars" roared down the crowded slopes of Malaysia's Mount Kinabalu after its earthquake, a witness said, as authorities on Sunday raised the death toll in the disaster to 16.

Six Singapore primary school students and a teacher who were on an excursion to the peak were among those killed when the 6.0-magnitude quake struck Friday morning, sending landslides crashing downward.

An international military intervention is needed to end unrest in Libya, where the Islamic State group is gaining a foothold, Spanish Defense Minister Pedro Morenes said in an interview published Saturday.

"We went to Afghanistan to stop all of that from coming here, we are in Iraq, Mali or Somalia with the same objective. And now we have it nearby. Something may need to be done," he told the top-selling Spanish daily El Pais when asked if there would be a military intervention in Libya.

The hunt for missing Malaysia Airlines Flight MH370 will not be expanded beyond its current area without specific new leads, Australian officials said Wednesday, dousing relatives' hopes the search could last beyond early next year.

In April, more than a year after the plane vanished en route from Kuala Lumpur to Beijing with 239 people on board, Malaysia, Australia and China announced that the search zone would double in size.

An Asia-Pacific security summit was briefly put on lockdown Sunday after police shot dead a local motorist who tried to flee a checkpoint in a car later found to contain drugs, officials said.

The three-day Shangri-La Dialogue attended by U.S. Defense Secretary Ashton Carter and counterparts from around the world along with top military officials ended at midday Sunday.

Fourteen people -- 13 Chinese nationals and a Malaysian -- were missing Wednesday after their sand-carrier barge capsized in Singapore waters, officials said, as authorities despatched naval and coast guard vessels to search for them.

Singapore's Maritime and Port Authority (MPA) said it had received reports that one Chinese crew member was rescued by the Malaysian Maritime Enforcement Agency.

Singapore on Monday condemned Iranian forces for firing warning shots in the Gulf at a commercial ship registered in the Asian city-state, calling it a "serious violation of international law".

The Maritime and Port Authority (MPA) also urged Tehran to investigate Thursday's incident involving the Singapore-flagged Alpine Eternity which it said was in international waters.

Two French warships docked in the commercial hub of Shanghai on Saturday, which diplomats said marked the first visit to China by French naval vessels since 2013.

The "Dixmude", which serves as a helicopter carrier, and the frigate "Aconit" pulled into port at a naval base in northern Shanghai on Saturday morning, greeted by Chinese military officers waiting on the dock with flowers and a band.