Reporter Hamdi al-Bokari and crew members Abdulaziz al-Sabri and Moneer al-Sabai were last seen Monday night in Taiz, a city in southern Yemen that's been the scene of heavy fighting for months now, the Qatari broadcaster said.
The network said it was "in contact with related parties in Taiz" to find the men and ensure their safety.
In a statement late yesterday night, Al-Jazeera's acting director-general Mostefa Souag called for the men's immediate release.
Journalists should have the freedom to do their work without the fear of intimidation, abduction or unlawful arrest."
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The network said al-Bokari, a Yemeni national, has worked for Al-Jazeera's Arabic channel since 2006. Al-Sabri is also a reporter for Al-Masdar newspaper, while al-Sabai works as a driver, according to the New York-based Committee to Protect Journalists.
Yemen's civil war began when Shiite rebels known as Houthis took control of the capital, Sanaa, in September 2014. In March, a coalition of countries led by Saudi Arabia began airstrikes and later, a ground operation to retake the country from the Houthis, who are allied with forces loyal to Yemen's former president and have received support from Iran.
For months, residents and aid groups say the Houthis have been indiscriminately shelling Taiz and blocking the delivery of humanitarian aid there.
Yemen's conflict has killed some 5,800 people since March and left over 80 percent of the country's population in dire need of food, water and other aid, according to the United Nations.
Journalists also have been targeted in the conflict. Houthis have detained reporters while at least four journalists have been killed in airstrikes by the Saudi-led coalition, according to the Committee to Protect Journalists.