A Somali commander says government and African Union troops have destroyed al-Shabab's defense lines in the key port city Kismayo.

Colonel Yasin Noor Gas spoke with VOA from the frontlines on Tuesday.

He said pro-government forces were in the village of Jana Abdalle, about 60 kilometers outside Kismayo and planned to move in within two days.

“Most of their defense lines were destroyed, there is insignificance presence. Our plan is to enter the town after a day or two,” he said.

Kismayo is al-Shabab's largest remaining stronghold in Somalia.

According to witnesses, al-Shabab fighters began leaving the city and moving heavy weaponry to surrounding towns on Sunday.

A spokesman for a pro-government militia said militants were no longer stationed at defense positions on Tuesday.

The U.N. Refugee Agency says more than 2,000 people have fled the port town since Sunday.

In an interview with VOA on Tuesday, spokesman Andreas Needham said that brings the number of people displaced from Kismayo this month to about 4,600.

Kismayo is critical to al-Shabab because it offers access to the sea and is near a massive forest where it operates training camps.

The al-Qaida-allied group has lost significant ground to pro-government, Kenyan and Ethiopian forces who launched major offensives last year.