How many time have we seen someone try and help these people only to be killed in return?

(MSNBC) — A gunman riding on the back of a motorcycle shot to death an American teacher in the city of Taiz, Yemen, on Sunday, a high-ranking government official there told NBC News.

The official said the teacher, an adviser at a Swedish-affiliated institute, died immediately after he was struck by gunfire Sunday morning while in a vehicle. Taiz is about 50 miles south of the Yemeni capital of Sanaa.

Officials from the institute identified the victim as Joel Shrun and said he was born in 1983.

A group linked to al-Qaida claimed responsibility. “This operation comes as a response to the campaign of Christian proselytizing that the West has launched against Muslims,” an unidentified person said in a text message to journalists, claiming responsibility on behalf of the Ansar al-Sharia (Partisans of Islamic Law).

Taiz has been a hotbed of opposition during Yemen’s revolution. Al-Qaida has taken advantage of the security vacuum in Yemen during the revoltion and extended its presence and authority in the country. Al-Qaida is in control of two cities in the south and have staged attacks on the Yemeni police and military, the latest killing more than 150 soldiers.