KARACHI, Pakistan — An American citizen was critically wounded in what was apparently a militant attack on Thursday in the southern port city of Karachi.

The American, identified as Debra Lobo, 55, was shot twice in her car by two men on a motorcycle as she left work on Thursday afternoon to pick up her husband and daughter, the police said. Ms. Lobo, a longtime resident of Karachi, works at the Jinnah Medical and Dental College, a private medical school, as the vice principal of student affairs.

“She was critically injured — one bullet hit her right cheek and passed out of the left, and another bullet was lodged in her right arm,” said Syed Pir Mohammad Shah, a senior police officer for the district.

A little-known group calling itself the Daulah al-Islamiyyah claimed responsibility for the attack. The gunmen appeared to have scattered leaflets in English and Urdu at the site of the attack. Titled “We Will Burn America,” the typed notes claim to be from “Lions of Daulah al-Islamiyyah, the Falcons of our Caliph” and state that they had “killed this Kansas lady ‘Lobo.’”