* PM Ardern to join mourners near Al Noor mosque
* Friday call to prayer to be broadcast nationally
* NZ bans types of semi-automatic weapons used in attack
* NZers encouraged to wear headscarves in show of support
By Tom Westbrook
CHRISTCHURCH, March 22 (Reuters) - New Zealanders prepared for nationwide prayers on Friday to mark one week since a mass shooting at two mosques in Christchurch killed 50 worshippers.
Prime Minister Jacinda Ardern will lead thousands of mourners expected to gather at a park in front of the Al Noor mosque, where most of the victims died, for a prayer followed by two minutes of silence.
Ardern, who has labelled the attack as terrorism, announced a ban on military-style semi-automatic and assault rifles under tough new gun laws on Thursday. prime minister is expected to be accompanied in the Christchurch prayers with community leaders and other foreign dignitaries.
The Muslim call to prayer will be broadcast nationally across all free-to-air TV and radio stations.
Armed police have been guarding mosques around New Zealand since the attacks. Police said there would be a "heightened presence" on Friday to reassure those attending weekly prayers.
Candlelight vigils continued until late on Thursday across the country, while government officials worked through the night to prepare the mosque and the bodies of the deceased for a mass burial that expected after the prayers.
“All the bodies are washed. We finished around 1.30 a.m. this morning. It was our duty. After we finished there was a lot of emotion, people were crying and hugging," said a body washer in Christchurch who gave his name as Mo.
Newspapers across the country ran full-page memorials with the names of the victims, and a call for national mourning.
"A call to prayer...in unity there is strength," New Zealand Herald said on its front page.
Australian Brenton Tarrant, 28, a suspected white supremacist who was living in Dunedin, on New Zealand's South Island, has been charged with murder following the attack.
He was remanded without a plea and is due back in court on April 5, when police said he was likely to face more charges.
Twenty-eight people wounded in the attacks remain in hospital, six in intensive care.
Most victims were migrants or refugees from countries such as Pakistan, India, Malaysia, Indonesia, Turkey, Somalia, Afghanistan and Bangladesh.
Muslims account for just over 1 percent of New Zealand's population, a 2013 census showed, most of whom were born overseas.
On social media, New Zealanders of all religions were being encouraged to wear headscarves on Friday to show their support for the Muslim community.
The #headscarfforharmony movement was trending on Twitter on Friday, with people posting photos of themselves in the Muslim attire.
(Writing by Praveen Menon; Editing by Lincoln Feast)