At least 40 martyred in terrorist attacks on 2 mosques in Christchurch, New Zealand.

Christchurch -- At least forty people were dead and more than 20 are seriously injured after a heavily armed gunman clad in military-style gear opened fire at a mosque in the center of Christchurch, New Zealand, on Friday.

A second mosque was also targeted in what New Zealand Prime Minister Jacinda Ardern called a well-planned "terrorist attack" making for "one of New Zealand's darkest days."

Authorities said they had four people in custody - three men and one women - but later clarified that only three were believed to have been involved in the violence. Police also deactivated a number of improvised explosive devices that had been attached to vehicles used by the suspects. Counterterrorism forces were activated across New Zealand and Australia.

Portions of the ghastly attack were broadcast live on social media, adding a new dimension to the scourge of gun violence - one sure to put more pressure on social media companies already under scrutiny about how they police their platforms.

Schools and public...