Sri Lanka Attacks: What We Know and Don’t Know – The New York Times

• The deadliest explosion was at St. Sebastian’s Church in Negombo, about 20 miles north of Colombo, where more than 100 were killed.

• At least 28 people were killed at the Zion Church in Batticaloa, on the other side of the island on its eastern coast. St. Anthony’s Shrine, a Roman Catholic church in Colombo, was also attacked, with an unknown number of dead. Witnesses described “a river of blood” there.

• The three hotels attacked, all in Colombo, were the Shangri-La, the Cinnamon Grand and the Kingsbury.

• People from more than a dozen foreign countries were killed, along with many Sri Lankans. Several of the victims were Americans, the authorities said. Others were Australian, British, Chinese, Dutch, Indian, Portuguese, Japanese and Turkish citizens, according to officials and news reports.

What we don’t know about the attacks

• Sri Lankan officials have yet to confirm if the so-called leader killed in the attack was Mohamad Zaharan, the radical Muslim lecturer mentioned in a security memo as the head of National Thowheeth Jama’ath who is believed to have organized the bombings.

• How two small, obscure groups — one of which was previously best known for desecrating Buddhist statues — managed to pull off sophisticated, coordinated attacks.

• The extent to which the Islamic State or other international terrorist networks may have helped with the attacks.