KHARTOUM, Feb. 14 (Xinhua) -- At least 12 people went missing on Saturday after a boat carrying 16 passengers capsized in the Wad Al-Zaki area in central Sudan's White Nile State, according to volunteers and eyewitnesses.

"A ferry carrying 16 people, including women, sank in Wad Al-Zaki. Four passengers were rescued, while search operations are still underway," the Sudan Doctors Network, a volunteer group, said in a statement.

An eyewitness told Xinhua that the boat sank while crossing between the village of Wad Al-Jatra on the western bank of the White Nile and Wad Al-Zaki on the eastern bank to attend a wedding, with 12 people reported missing.

Photos and videos circulated on social media showed small boats combing the river as volunteers joined rescue efforts, while dozens of residents gathered along the banks of the Nile to follow the search.

The incident came just days after another ferry sank in River Nile State in northern Sudan, killing 21 people. The Sudan Doctors Network called on the relevant authorities to review all river boats, enforce safety regulations and ensure life-saving equipment to prevent similar tragedies.

In Sudan, where bridges are scarce especially in rural areas, frequent accidents involve overloaded traditional wooden boats used to cross the Nile. Civil defense authorities have repeatedly warned of their dangers, particularly during flood seasons. ■