(CNN) - Churches are opening their doors after mosques were told to close for security issues in the wake of the Christchurch, New Zealand, terrorist attacks. Mosques are receiving messages of solidarity and flowers. A fundraiser for the victims is nearing $400,000. And a UK-based national forum for Christian-Muslim engagement is calling on Christians to go along to Friday prayers at their local mosques -- a call the archbishop of Canterbury endorsed.
These are only a few examples of how people and institutions are showing solidarity and offering help to Muslim communities all over the world after Friday's shooting attacks on two Christchurch mosques that killed at least 49 people and seriously injured 20 others.
Here's how you can help the New Zealand victims
In some of the worst terror attacks and mass shootings of recent years, Muslim communities have stepped up to help in different ways. In the aftermath of October's Tree of Life Synagogue shooting in Pittsburgh, for example, the Muslim-American nonprofit groups CelebrateMercy and MPower Change launched a crowdfunding appeal that raised thousands for the victims.
They are opening their doors
Immediately after Friday's attacks in Christchurch, the Te Atatū Baptist Church in Auckland, New Zealand, announced on Facebook it was opening its doors to Muslims because mosques had been closed.
"Tonight we will open up The Meeting Place from 7pm to 8pm for prayer for Christchurch. Come and light a candle, say a silent prayer and stand with our fellow kiwis. All welcome," the post said.
"We especially invite the Muslim community whose mosques have been closed, to come and join us tonight."
Other landmark churches, such as St. Paul's Cathedral in London, said it was offering prayers during daily services for those affected by the shootings in New Zealand. "We pray too for our Muslim friends and (neighbors) here and around the world," the church said on Twitter.
The UK's national forum for Christian-Muslim dialogue, the Christian Muslim Forum, called on Christians to go to Friday prayers at their local mosques "to stand in solidarity."
"The devastating attacks in Christchurch bring us together in grief and in our determination to fight hatred with friendship," it announced on Twitter with the hashtag #WeStandTogether.
"Churches are visiting mosques across the country today in solidarity," the group told CNN. The message was retweeted in support by Justin Welby, the archbishop of Canterbury.
They are expressing solidarity
People started writing supportive messages using the hashtag #TheyAreUs to signal that Muslims are welcome in New Zealand. The phrase gained traction after New Zealand Prime Minister Jacinda Ardern used the words when discussing the attack on Friday.
Ardern said migrants and refugees could have been caught up in the attack.
"They have chosen to make New Zealand their home and it is their home. They are us," she said. "The person who has perpetuated this violence against us is not."
They are holding vigils
Meanwhile, peaceful vigils are already being held in New Zealand and across the UK.
People also are leaving messages of support and flowers at the entrance of mosques, including the Finsbury Park mosque in north London, the target of a June 2017 terror attack that left one Muslim worshipper dead.
Meanwhile, the New Zealand Council of Victim Support Groups, a local charity, has launched a crowdfunding effort for the victims that is nearing $400,000.
In another show of solidarity, the New Zealand Jewish community shut its synagogues on Shabbat for the first time, according to a tweet by Isaac Herzog, head of the Jewish Agency for Israel.