DAKAR, Senegal—A Mauritanian website says it has received a video from al-Qaida's North African arm that appears to indicate seven foreigners taken hostage in west Africa are alive.

The ANI website, which has previously been used by al-Qaida in the Islamic Maghreb, or AQIM, said the video was released Monday, three years to the day after four of the hostages, all French, were kidnapped from the French-operated Areva uranium mine in the northern Niger town of Arlit.

The other three hostages were kidnapped from the northern Mali town of Timbuktu in November 2011. They are from the Netherlands, South Africa and Sweden.

The video was not shown online.

AQIM was one of three Islamic extremist groups that controlled northern Mali until a French-led military intervention drove them out.