Strong currents forced Indonesia to expand the search area for the crashed AirAsia QZ8501 plane Tuesday, as rough seas and bad weather pushed debris and made it difficult to reach suspected chunks of the fuselage on the ocean floor.

With only 37 bodies recovered since AirAsia Flight 8501 crashed Dec. 28, there are also concerns that it will become harder to find the remaining corpses.

”Time is of the essence,” said the National Search and Rescue Agency’s director of operation, Suryadi B. Supriyadi. ”But it seems like it is hard to beat the weather.”

The search operation will expand by about 185 square kilometers (70 square miles), search and rescue chief Henry Bambang Soelistyo said.

Muslim clerics recite Koran verses as they perform a prayer for victims of AirAsia flight QZ 8501 inside an Indonesian Air Force NAS 332 Super Puma helicopter flying over the Java Sea off Pangkalan Bun, January 6, 2015. Search teams including divers took advantage of a let-up in bad weather on Tuesday to try to reach the wreckage of an AirAsia jet that crashed nine days ago, and to recover bodies and find its black box flight recorders. Indonesian officials believe they may have located the tail and parts of the fuselage of the Airbus A320-200 at the bottom of the Java Sea, but strong currents, high winds and big waves have hindered attempts to investigate the debris. REUTERS

Dozens of new air carriers have popped up in Indonesia in recent years to meet the industry’s booming demand, but a string of deadly accidents has raised concerns about safety.

Experts say poor maintenance, rule-bending and a shortage of trained personnel are largely to blame. Infrastructure has also failed to keep pace with exploding demand.

The country’s transportation ministry said it was cracking down after it was discovered that Flight 8501 did not have a permit to fly between Surabaya, Indonesia, and Singapore on the day of the crash. It suspended two ministry officials and five workers at Surabaya’s main airport Tuesday for allowing the flight. Others are still under investigation.

All AirAsia flights on that route also have been canceled for the time being.

Java Sea Off Pangkalan Bun : Muslim clerics perform a prayer for the victims of AirAsia Flight QZ 8501 inside an Indonesian Air Force NAS 332 Super Puma helicopter flying over the Java Sea off Pangkalan Bun, Central Borneo, Indonesia where the ill-fated jetliner went down, on Tuesday, Jan. 6, 2015. The Singapore-bound plane crashed into the sea 42 minutes after taking off on Dec. 28. AP

It is not known what caused the Airbus A320 to crash into the Java Sea 42 minutes after takeoff, though Indonesia’s Meteorology, Climatology and Geophysics Agency says bad weather appears to have been a factor.

Just before losing contact, the pilot told air traffic control he was approaching threatening clouds, but was denied permission to climb to a higher altitude because of heavy air traffic. No distress signal was issued.

Sonar has identified five large objects that are believed to be pieces of the fuselage on the ocean floor, but strong currents, silt and mud have kept divers from seeing or reaching the objects.

No pings have been detected from the plane’s all-important cockpit voice and flight data recorders. That’s because high waves have prevented the deployment of ships that drag ping locators. The batteries in the pingers on the black boxes are likely to go dead in about 20 more days.

”We are confident that rescuers would be able to locate them in time,” said Nurcahyo Utomo, an investigator for Indonesia’s National Committee on Transportation Safety.

The search for the remaining 125 bodies has been exhausting for family members anxiously waiting to identify and bury their loved ones.

Eight Islamic clerics flew in a helicopter over the site Tuesday and scattered rice into the sea, a local tradition, and prayed for those who perished.