ISLAMABAD — A bomb blast in a park in the eastern Pakistani city of Lahore on Sunday has killed 44 people and wounded 91, a health official said. Many of the injured are in a critical condition, Salman Rafiq, a health adviser to the chief minister of Punjab province said. The explosion took place near the children’s rides in Gulshan-e-Iqbal park, local police chief Haider Ashraf said.