TOKYO, March 7 (Xinhua) -- The Japanese government on Wednesday insisted the U.S. military report cases of mishaps and accidents more promptly following a serious delay in it being informed of a part falling off a F-15 fighter jet during a flight.

On Feb. 27, an antenna-like object weighing 1.4 kg fell off the jet which was stationed at the U.S. Kadena Air Base in Okinawa.

But Japan's Defense Minister Itsunori Onodera said the government was only informed of the mishap on Monday.

"We would like to request the U.S. side to put top priority on confirming safety," Onodera told a press briefing on the matter in Tokyo, adding that he was "baffled" that the information, delayed as it was, was also received through entirely the wrong channels.

According to standard protocol, such mishaps should be reported to the government through the local defense bureau, but in this case the government here was inexplicably informed through the Foreign Ministry.

Japan's top government spokesperson also took aim at the U.S. military's lax safety procedures and said it was regrettable that it took as long as six days for the pertinent information on the aircraft mishap to reach the government.

"It is truly regrettable that it was not reported immediately," Chief Cabinet Secretary Yoshihide Suga said.

He added that the Japanese side had reiterated its position that it wants all such U.S. military-linked incidents reported in a timely manner and for the cause to be determined and rectified swiftly to prevent such mishaps from happening again.

While the part suspected of falling from the jet caused no injury or damage to property, according to the government's latest information, the incident has reignited concerns from both central and local governments about the safety standards employed by the U.S. military, particularly in Japan's southernmost prefecture of Okinawa.

The latest mishap comes on the heels of a slew of other worrying incidents involving U.S. military aircraft based here.

These include an incident last month, which saw an F-16 fighter jet from the U.S. Misawa Air Base in the northeastern prefecture of Aomori jettisoning two fuel tanks into a lake following an engine fire.

There were as many as 10 fishing boats in the lake at the time and fishing had to be suspended following the incident, causing a huge loss in earnings to the local fisherman.

The Lake Ogawara fishery association decided to completely halt fishing in the lake until the fuel oil had been retrieved.

According to Japan's public broadcaster NHK, the Lake Ogawara fishery association has estimated that the fishermen are losing around 28,000 U.S. dollar a day, due to the incident.

The recovery and cleanup work was only completed by Japan's Maritime Self-Defense Force (MSDF) on Wednesday and involved oil and debris from the tanks being removed from the lake.

MSDF forces, sources with knowledge of the matter said, had retrieved a total of 87 parts and fragments of the fuel tanks by Tuesday.

With U.S.-military-linked accidents very much in the spotlight recently, an incident involving a heavy, metal-framed window falling from a CH-53E transport helicopter in December. The window crashed onto the playground of an elementary school just meters from where 50 children took exercise classes.

The accident continues to unnerve the local community near the U.S. Marine Corps Air Station Futenma in Okinawa, where the chopper was based.

And in January alone, three helicopters also based at the controversial U.S. Marine Corps Air Station Futenma, made emergency "off base" landings, sparking local and national indignation and fear.

As for the most recent incident, Deputy Okinawa Gov. Moritake Tomikawa underscored the fact that the U.S. military is slow in providing essential information.

"This is out of the blue. They are slow in providing information," he was quoted as saying Wednesday.

Kadena town mayor Hiroshi Toyama also weighed in, demanding that such incidents be reported more promptly.

"We have been asking the U.S. military to prevent a recurrence every time there is a mishap, but they keep on happening," Toyama said.