* Thousands march in Yangon, Naypyitaw, other cities
* Journalist among the latest in wave of arrests
* Suu Kyi in good health, a party aide says(Adds junta appeal to civil servants)
Feb 13 (Reuters) - Myanmar's junta on Saturday suspendedlaws constraining security forces from detaining suspects orsearching private property without court approval and orderedthe arrest of well-known backers of mass protests against thismonth's coup.
A series of announcements came on the eighth day ofcountry-wide demonstrations against the Feb. 1 takeover anddetention of elected leader Aung San Suu Kyi, which halted anunsteady transition to democracy that began in 2011.
The announcements bore echoes of the near half-century ofmilitary rule before reforms began, when the Southeast Asiancountry was one of the world's most repressive and isolatedstates.
An order signed by military ruler General Min Aung Hlaingsuspended three sections of laws "protecting the privacy andsecurity of the citizens", which had been introduced during thegradual liberalisation.
Those sections include the requirement for a court order todetain prisoners beyond 24 hours and constraints on securityforces' ability to enter private property to search it or makearrests. The suspensions also free up spying on communications.
The statement gave no specific end date.
The coup has prompted the biggest street protests in morethan a decade and has been denounced by Western countries, withthe United States announcing some sanctions on the rulinggenerals and other countries also considering measures.
As anti-coup protests sprang up again in the biggest cityYangon, the capital Naypyitaw and elsewhere on Saturday, thearmy said arrest warrants had been issued for seven high profilecritics of military rule over their comments on social media.
People should inform the police if they spot any of thosenamed and will be punished if they shelter them, the army's TrueNews information team said in a statement.
It said cases had been filed under a law which provides upto two years jail for comments that could cause alarm or"threaten tranquillity".
On the wanted list is Min Ko Naing, 58, who was imprisonedfor most of the time between 1988 and 2012, and who has beenprominent in encouraging protests and a civil disobediencemovement followed by a swathe of government workers.
Reuters was not immediately able to reach him for comment.
Others with warrants against them included "Jimmy" Kyaw MinYu, also a veteran of the 1988 student uprising, and singer "LinLin" Htwe Lin Ko.
"I am so proud to have a warrant issued along with Min KoNaing. Catch me if you can," said Ei Pencilo, to her more than1.6 million followers on Facebook.
Like several others named, she worked with Suu Kyi'sNational League for Democracy (NLD), which won a landslide in aNovember election the army alleged to be tainted with fraud - anaccusation dismissed by the electoral commission.
Protests in support of Suu Kyi and the election sprang upacross Myanmar again on Saturday in spite of a junta call forpeople to avoid mass gatherings due to the coronavirus epidemic.
The junta also appealed to civil servants who have beenfollowing the civil disobedience campaign to return to work,with a threat of possible disciplinary action against those whodo not.
The United Nations human rights office said on Friday morethan 350 people have been arrested in Myanmar since the coup.
Journalist Shwe Yee Win, who had reported on opposition tothe coup in the western town of Pathein, was taken away bypolice and soldiers on Thursday and has not been heard fromsince, her TimeAyeyar news website and her mother said.
"I am really worried," said Thein Thein, now looking afterher daughter's one-year-old child.
The government did not respond to requests for comment.
The Assistance Association for Political Prisoners voicedconcern about a wave of overnight arrests.
"Family members are left with no knowledge of the charges,location, or condition of their loved ones. These are notisolated incidents, and nighttime raids are targeting dissentingvoices," it said in a statement.
Suu Kyi, for decades the standard bearer of the fight fordemocracy in Myanmar, faces charges of illegally importing andusing six walkie-talkie radios.
NLD press officer Kyi Toe said on Facebook that she washealthy under house arrest in the capital Naypyitaw.
The coup and detentions have prompted anger from Westerncountries and the 47-member U.N. Human Rights Council adopted aresolution on Friday calling on Myanmar to release detainees andrefrain from using violence against protesters.
The United States this week began imposing sanctions on theruling generals and some businesses linked to them.
(Reporting by Reuters staffWriting by Matthew TostevinEditing by William Mallard, Angus MacSwan and Mark Potter)