The plane came from Cebu and was bound for Naga when it called for an emergency landing to Masbate airport around 4 p.m.
Robredo was the keynote speaker at the Community Investigative Support National Summit of the Criminal Investigation and Detective Group in Cebu City Saturday morning. He was scheduled to take a Cebu Pacific flight to Manila, but he decided to take a private plane instead to Naga, where he was former mayor.
DILG Secretary Jesse Robredo
"Before it (the plane) could land at the Masbate City airport, it crashed at sea around 150 meters away from the airport," said Masbate Vice Governor Vince Revil.
The plane crashed around 100 meters away from the shoreline, said Transportation Secretary Manuel Roxas II. The area was five to six meters deep, reports said.
The crash happened around 4:20 p.m. due to engine failure, according to official report from the military's operations center.
Armed Forces of the Philippines Southern Luzon Command spokesman Colonel Generoso Bolina said the aircraft crashed at the waters of Ibiningay village.
The officials said Robredo's close-in bodyguard identified as Police Senior Inspector Jun Abrazado was rescued but he sustained fractures.
"Jun Abrazado was recovered alive, he is okay, but he sustained injuries. He is currently under the custody of the PNP (Philippine National Police). But the three others (Robredo and the pilots) could not be found," Bolina added.
Vice Governor Revil said Abrazado "insisted on going back to the site to pinpoint where the plane crashed."
Robredo was not able to get out of the plane, according to Army Commander Julian Pacatan, quoting Abrazado.
Abrazado also said the pilot decided to ditch the aircraft to the water after one of the plane's propellers stopped.
The twin-engine Viper Seneca aircraft, according to Cebu City Traffic Operations Management chair Sylvan Jakosalem, was owned by pilot Captain Jessup Bahinting of Aviatours.
Bahinting is one of those missing off Masbate.
Revil said rescue and retrieval operations are ongoing as of this posting Saturday. Divers and Coast Guard personnel from Cebu and Naga, as well as Masbate, were deployed to the area to search for the missing passengers.
Fisherfolk in Masbate have also been helping in the search, said DILG Undersecretary Rico Puno.
He said he called all units of the Philippine Navy, maritime groups, the Philippine National Police to also help in the operations.
"All hospitals in Masbate were also told to prepare," he added.
He also confirmed that Robredo was able to talk to his wife minutes before the accident.
"He told his wife that the aircraft was encountering problems," Revil said.
he said they have yet to confirm the status of the secretary, although there have been reports that Robredo was rescued by a fisherman.
"We are doing everything we can for rescue and retrieval operations," said Revil.
"Siya (Robredo) ang isa sa pinakamatinong tao kaya ipagdasal natin siya," Roxas said.
Presidential spokesperson Edwin Lacierda, for his part, assured that the public will be updated about what happened.
"We will be updating the public as details are confirmed: speculation is not useful at this point," he said.
The Office of the Presidential Spokesperson appealed to the public to join President Benigno Aquino III and his Cabinet in prayer for Robredo’s successful rescue.
"As search and rescue efforts for Secretary Jesse Robredo and party continue…we ask that the efforts be allowed to continue unimpeded and without speculation on the part of the public. We must remain focused on the task: to find Sec. Robredo and his companions, and to bring them to safety," it said.
A prayer vigil is now ongoing at the National Shrine of the Divine Child in De La Salle University in San Juan City.
Robredo is an alumnus of the De La Salle University, having obtained undergraduate degrees in Industrial Management Engineering and Mechanical Engineering, according to his biography.
Born in May 27, 1958, Robredo became popular for the transformation of Naga City from a lethargic city into one of the "Most Improved Cities of Asia."
He is an Edward Mason Fellow and a graduate of Masters in Public Administration at the John F. Kennedy School of Government at Harvard University.
He was a multi-awarded local chief executive of Naga City.
Robredo was recipient of 14 major individual awards, including the 2000 Ramon Magsaysay Award for Government Service, the 1996 Outstanding Young Persons of the World (TOYP) Award, the Outstanding Young Men of the Philippines (TOYM), 1998 Konrad Adenauer Medal of Excellence as Most Outstanding City Mayor of the Philippines and the first ever "Dangal ng Bayan" Award of the Civil Service Commission.