The Canadian soldier who was attacked with an axe in Afghanistan on March 4 is showing some improvement.

Capt. Trevor Greene opened his eyes Friday in what his father Richard Green describes as "a slight improvement." It was "a small step, but a great one," said the elder Green.

Capt. Greene, 41, is described as being in serious, but stable condition in a U.S. military hospital in Landstuhl, Germany. He had been struck in the back of the head with an axe during a sit-down meeting with tribal elders in a village about 70 kilometres north of Kandahar.

Canadian soldiers immediately gunned down the attacker. Military officials believe the attacker, in his 20s, was a Taliban insurgent, although a village elder disputes that claim.

More violence in Afghanistan

In other developments, Two Afghan policemen's bodies were found decapitated in the desert on Saturday. They had been kidnapped late Friday, according to Afghan officials.

The low-ranking policemen were taken from their homes in southern Helmand province, the heart of Afghanistan's opium poppy region.

This was the latest violence to hit the area after Afghan security forces started a campaign to get rid of hundreds of hectares of opium poppies, used to make heroin.

Roadside bombs in Helmand also killed a policeman and two Afghan soldiers in two separate incidents this week.

Recent weeks have seen an increase in violence in Helmand, which makes one-quarter of Afghanistan's opium.

Taliban rebels reportedly said they would defend opium farmers. But there haven't been any attacks on the heavily-guarded government workers who are destroying poppy fields.

The U.S. and British governments are funding the destruction of the poppy fields.

Afghanistan supplies 90 per cent of the world's opium and heroin. The country's government has been criticized for not being tough enough on the growing drug trade, even though millions of foreign funding has been spent fighting the drug problem.

Earlier this week, the Afghan government and the United Nations predicted the cultivation of opium poppies would increase in large parts of the country this year.

With files from The Canadian Press and the Associated Press