China and Russia on Sunday launched their first joint naval exercises amid tensions between China and its Asian neighbors over regional territorial claims.

The six days of drills are taking place in the Yellow Sea off China's east coast, the official China News Service said, adding they were the first dedicated exercises involving the two navies.

Four new species of freshwater crab, bright purple in color, have been discovered in the biologically diverse Philippines, according to a scientific paper.

The tiny crustaceans were found in streams in remote areas of the Palawan island group, according to a team led by Hendrik Freitag, of Germany's Senckenberg Museum of Zoology.

Two people were killed and five others were wounded when a bomb exploded on a bus in the southern Philippines on Wednesday, the regional military commander said.

The explosion occurred as the bus was pulling into a terminal in Carmen, a town on the restive island of Mindanao that is home to a long-running Muslim insurgency, Lieutenant Colonel Benjie Hao told reporters.

A powerful booby trap bomb killed one Philippine soldier and wounded 27 others as they patrolled a former stronghold of al-Qaida-linked militants on Tuesday, the military said.

The soldiers were patrolling the outskirts of a remote camp captured last month from Abu Sayyaf extremists when the device went off, local army commander Colonel Ricardo Visaya told Agence France Presse.

Dozens of black-clad gunmen armed with grenades and bombs stormed a southern Philippine jail trying to free a detained comrade, but they were repulsed by police in a chaotic night battle that killed three people, officials said Monday.

Fifteen people were wounded, most of them civilians caught in the firefight late Sunday outside Kidapawan's city hall compound and along a key commercial road. Military and police officials blamed former members of the Moro Islamic Liberation Front, but a spokesman for the Muslim rebel group denied the claim.

The death toll from a strong quake this week in the central Philippines rose to 39 on Friday, with dozens of missing feared dead, a disaster official said.

Rescuers recovered five bodies in the landslide-hit central island of Negros four days after it was rattled by a 6.7-magnitude quake that flattened homes, destroyed bridges and crumbled mountainsides.

Philippine rescue officials said Wednesday they are losing hope of finding anyone alive among 71 people still buried in landslides set off by a powerful earthquake. So far, 26 bodies have been recovered and identified.

President Benigno Aquino III flew to the disaster area in central Negros Oriental province and gave orders to speed up the reconstruction of roads and bridges that collapsed when the magnitude-6.9 quake struck Monday.

A 6.0-magnitude quake struck off the eastern coast of the Philippines on Saturday, the U.S. Geological Survey said, but no tsunami warning was immediately issued.

The quake hit at 9:09 pm local time (13:09 GMT) off the island of Samar, at a depth of 60 kilometers around 100 kilometers north of the city of Guiuan, USGS said.

Philippine authorities said Thursday they had failed to find two European birdwatchers in the crucial 24 hours after their abduction and warned Islamic militants may be holding them.

Hundreds of Marines quickly joined the search for Swiss national Lorenzo Vinciguerra, 47, and Dutchman Ewold Horn, 52, who were seized by armed men on a tiny island in the lawless south of the country on Wednesday.

The Philippine army said it killed three senior leaders from the al-Qaida linked Abu Sayyaf and Jemaah Islamiyah militant organizations in an air raid on a remote southern island on Thursday.

The three were among 15 militants killed on Jolo, a jungle-infested island where Abu Sayyaf members are suspected to be holding kidnapped foreigners, regional military commander Major General Noel Coballes told Agence France Presse by phone.