A Malaysia Airlines plane with 166 people aboard landed safely early Monday after turning back to Kuala Lumpur due to a landing gear problem, the carrier said.

"The aircraft's right-hand landing gear malfunctioned upon takeoff and was forced to turn back to Kuala Lumpur," said the airline, which is still reeling from the loss and presumed crash of flight MH370.

Suspected Islamic militants have freed a Filipino engineer they abducted in the southern Philippines 53 days ago, the military said Sunday.

Bonifacio Salinas was seized by alleged members of the Abu Sayyaf group on the volatile southern island of Jolo in February along with his wife, Claire, who was freed a month later.

The effort to find missing flight MH370 is at a "very critical juncture", Malaysia's transport minister said Saturday as authorities mull whether to reassess a challenging search of the Indian Ocean seabed that has so far found nothing.

"The search for today and tomorrow is at a very critical juncture. So I appeal for everybody around the world to pray and pray hard that we find something to work on," Transport Minister Hishammuddin Hussein said.

Malaysia and Australia will sign a deal specifying who handles any wreckage from missing flight MH370 that may be recovered, including the crucial "black box" flight data recorders, local media reported Friday.

Malaysia is drafting the agreement "to safeguard both nations from any legal pitfalls that may surface during that (recovery) phase," the New Straits Times reported.

About 100 Malaysian Muslim activists protested Friday outside the US embassy against the coming visit by President Barack Obama, denouncing him as an enemy of Islam.

The demonstration underscored the delicate nature of Obama's trip to Muslim-majority Malaysia, which will make him the first siting U.S. president to visit in nearly half a century, a period marked by mutual distrust.

The mini-sub searching for missing flight MH370 dived on its fifth seabed mission Friday, officials said, testing the vehicle's recommended depth limits after failing to find any wreckage.

With no results to show since the Boeing 777 carrying 239 people disappeared on March 8, Australia's Prime Minister Tony Abbott has set a one-week deadline to locate the plane which is believed to have crashed in a remote area of the Indian Ocean west of Perth.

Malaysia warned Thursday that the search for flight MH370's wreckage in the vast depths of the Indian Ocean will be "huge", the latest sobering assessment by authorities involved in the challenging effort.

"When we look at salvaging (wreckage) at a depth of 4.5 kilometers (2.8 miles), no military out there has the capacity to do it," Transport and Defense Minister Hishammuddin Hussein told reporters in Kuala Lumpur.

A leading Malaysian politician who gained fame defending opposition leader Anwar Ibrahim in his sensational sodomy trials was killed in a road accident on Thursday, police said.

Karpal Singh, 73, died along with a longtime assistant when his vehicle collided with a lorry on a highway in the northern state of Perak in the early morning, said state police chief Acryl Sani Abdullah.

A mini-submarine making its second dive in the hunt for Malaysian jet MH370 encountered a "technical difficulty" and resurfaced Wednesday, officials said, after the first mission also aborted.

"The Autonomous Underwater Vehicle, Bluefin-21, was forced to resurface this morning to rectify a technical issue," Australia's Joint Agency Coordination Centre (JACC) said.

A mini-sub hunting missing Flight MH370 was set to sweep the Indian Ocean seabed again Tuesday after cutting short its first mission, as Malaysia vowed to reveal any “black box” data found.

The unmanned submarine equipped with sonar gear was deployed Monday night from the Australian ship Ocean Shield, which has spearheaded the hunt for the Boeing 777 that vanished on March 8 with 239 people aboard.