BENGHAZI, Libya (Reuters) - Air raids in the eastern Libyan city of Derna killed one child and wounded three more, a resident and medical sources said, the second time in a week that civilians have been killed by strikes there.

Military forces allied to Libya's eastern government have been carrying out regular air strikes in Derna which they say are targeting al Qaeda-linked militants.

The strikes on Wednesday hit the seafront promenade in Derna, resident Abdessalem al-Tajouri told Reuters. Last Thursday an air strike hit a residential area in Derna, killing a woman and three children.

Ahmed al-Masmari, a spokesman for the eastern military, said Derna residents had been helping al Qaeda and had to "take responsibility for their actions".

"We have warned residents in the city of Derna through statements from the operations room and the military headquarters not to cover up for al Qaeda or allow them to use residential districts to store weapons and ammunition."

Derna has long had a strong Islamist presence, and became a base for Islamic State militants in 2014. Rival Islamists and other local forces retook control of the city last summer and pushed Islamic State from its last footholds in Derna earlier this year.

Eastern military forces are also waging a military campaign against Islamists and other opponents in Benghazi, Libya's second city.

(Reporting by Ayman al-Warfalli, Writing by Aidan Lewis, Editing by Angus MacSwan)