VIENTIANE, May 3 (AFP) - A prominent activist and critic of the Laos government has been gunned down at a cafe in the capital Vientiane, with graphic footage of the murder published online by state media.

Communist Laos has long been criticised for its poor human rights record and failing to properly investigate the disappearances of government critics.

Human Rights Watch and Amnesty International condemned the murder and urged the Laos authorities to carry out a proper investigation.

Chilling security camera footage posted online by state news agency KPL on Monday shows a gunman in a brown shirt and black cap shooting Anousa "Jack" Luangsuphom twice on Saturday.

The gunman steps briefly inside the cafe, seemingly to confirm his target is there, before drawing a handgun from his waistband and re-entering to fire two shots at close range.

Anousa falls to the floor as two women in the cafe cry for help and the gunman makes his escape.

The footage shows the gunman carefully using a handkerchief to open and close the door, presumably to avoid leaving fingerprints.

The KPL report said police were investigating the incident and searching for suspects.

Contacted by AFP, police declined to comment on the investigation.

Anousa was the administrator of a popular Facebook page "Driven By Keyboard" which regularly posted critical views on the Laos government.

"R.I.P Jack Anousa. We all will never forget Jack," his friends wrote on the page. Others posted a picture of him with the hashtag JusticeForJack.

Amnesty International said a friend of Anousa had told them the attack had left activists even more afraid to speak out.

"I am devastated about the death, and also deeply scared about what may happen to me," the friend said, according to a statement from Amnesty.

Human Rights Watch said Anousa died on the way to hospital.

"The cold-blooded killing of a prominent young political activist in downtown Vientiane sends a spine-chilling message that no one in Laos who criticises the government is safe," Asia director Elaine Pearson said in a statement Wednesday.

"The Lao government should urgently conduct a credible and impartial investigation into Anousa's death and bring to justice all those responsible."

A number of critics of the poor, secretive state have died or gone missing in recent years.

Sombath Somphone, an award-winning campaigner for sustainable development, vanished in December 2012 after police pulled over his vehicle at a checkpoint in the capital.

Pro-democracy campaigner Od Sayavong has also not been seen since he went missing in Thailand in 2019.