By Yimou Lee

TAIPEI (Reuters) -Taiwan will issue new air-raid guidance for its citizens next week, according to security officials and internal planning documents reviewed by Reuters, learning lessons from Ukraine and Israel in case it needs to counter a Chinese military attack.

"Taiwan is looking very closely into the cases from Ukraine and Israel," a senior Taiwan security official briefed on the matter told Reuters. 

"Our people must know how to protect themselves, either at home or in office," said the official, who requested anonymity due to the sensitivity of the matter.

Authorities will update instructions on what people should do when air-raid alerts are issued, including for citizens who are not able to get into shelters in time or for those who are driving a car, according to the government planning documents. 

That includes instructions on hiding behind "at least two layers of walls" and "staying in the down position while opening your mouth slightly" in the scenario when people could not immediately get to an air-raid shelter. 

"In metropolitan Taiwan, the reality is that many residents of high-rise buildings may not be able to get to the designated air-raid shelters quickly within three minutes," a second security official said, adding the government is working to get citizens to learn "alternative" ways to protect themselves.

Civil defence drills including rehearsals on setting up emergency supply stations will be held across the island alongside Taiwan's main annual "Han Kuang" military exercises in July, which will last for an unprecedented 10 days, the two officials said. 

Taiwan has been preparing air-raid shelters across the island, including in subway stations and shopping malls, after Russia's invasion of Ukraine raised new fears about a Chinese invasion.

The capital of Taipei alone has more than 4,600 such shelters that can accommodate some 12 million people, more than four times its population. 

China views separately governed Taiwan as its own territory and has ramped up its military pressure over the past five years, including staging half a dozen rounds of war games. Taiwan's government rejects Beijing's sovereignty claims.

(Reporting By Yimou Lee; Editing by Ben Blanchard and Raju Gopalakrishnan)