BEIJING, Feb. 28 -- Following two accidents on landing, the Chinese Modern Ark 60 (MA-60) aircraft must be thoroughly checked, China's aviation watchdog announced on Friday .

All MA-60 should have their landing signal systems checked, said the Civil Aviation Administration of China.

Those with more than 6,400 take-offs should be grounded for checks. This will involve two domestic airlines, Joy Air and Okay Airways, and four airlines in Laos, the Philippines, Zimbabwe and Bolivia, the administration said.

A Joy Air MA-60 crashed during landing operation at Zhengzhou airport, in central China's Henan Province on Feb. 4 when the front landing gear suddenly retracted. There were no casualties.

On Feb. 25, an Okay Airways MA-60 had circled for about an hour and a half due to flaws in landing signal system before it landed safely in Shenyang, capital of northeastern China's Liaoning Province.

MA-60, introduced in the year 2000, is China's only home grown passenger aircraft in service.