Newly-displaced people in Somalia are facing a dire situation after the government launched another military operation against local fighters, Press TV reports.

Some 6,000 families have fled towns in the southern and central parts of the country over the past few weeks after Somali government forces backed by 22,000 African Union soldiers began a nationwide offensive against al-Shabab.

The United Nations says the displaced have fled the cities of Diinsoor and Baidoa in the Bay region and the city of Hudur in Bakool area.

The UN has also expressed concern about new reports on the displaced people in the country.

Humanitarian access remains a major challenge in Somalia due to volatile security conditions.

The UN says the displaced are in need of immediate humanitarian assistance, including shelter, water, food and health services.

The Somali government has stepped up its offensive against al-Shabab after the group attacked the presidential palace in February. More than a dozen people died in the assault.

Earlier this month, government forces together with African Union soldiers captured several strategic central towns that were previously held by al-Shabab, including the towns of Buloburde and Buqdaaqable as well as the village of Raan-Gaabo in the Hiran region.

The group, however, remains in control of large parts of rural areas in southern Somalia and continues to carry out attacks on the foreign troops in the country.

Al-Shabab fighters were driven out of the capital, Mogadishu, by the UN-mandated African Union Mission in Somalia (AMISOM), which is made up of troops from Uganda, Burundi, Djibouti, Sierra Leone and Kenya.

The country has been the scene of clashes between government forces and al-Shabab since 1991.