The Chinese government Thursday said safety checks on tail flaps of aircraft made by U.S. giant Boeing were just "routine inspections," after media reports said those checks indicated a "potential safety hazard".

Wednesday's National Business Daily (NBD) said the Civil Aviation Administration of China (CAAC) Monday issued an "Emergency Airworthiness Directive" for the "tail flap mechanism" of more than 400 Boeing 737 jets, which the newspaper said indicated a "potential safety hazard", quoting an unidentified source with the CAAC.

The CAAC Thursday posted a "clarification statement" on its website, saying it did order safety checks on the aircraft, but they were just "routine inspections" to ensure flight safety.

Altogether 160 aircraft covering six Boeing 737 models were involved, it said, differing from the reported number of "more than 400".

CAAC Vice Minister Li Jian said the airworthiness directive was a regular CAAC flight safety management procedure. The administration issued approximately 300 such directives last year to urge airline companies to strengthen daily safety checks.

It had altogether issued 6,502 airworthiness directives during the 1986-2009 period, he said.

The U.S. Federal Aviation Administration (FAA) last week issued a directive urging immediate inspections of the elevator tab control device on tail flaps of the six models of Boeing 737s, after a Ryanair jet was diverted from its destination due to severe vibrations.

The problem could result in loss of aircraft control and structural integrity, it said.

According to the directive on the FAA website, the Boeing Company Friday issued an alert service bulletin describing the problem and repair procedures.