TUNIS - Tunisia's defense minister Abdelkrim Zebidi called on the army for increased vigilance in securing the country's southern border with Libya, TAP news agency reported on Thursday.

Related readings: Libya rebels say retake Tunisia border crossing  China willing to fund projects in Tunisia  Tunisia: Land hit by Libyan mortar shells  Tunisia to file charges against ex-president

Zebidi who spoke to the soldiers and officers with the 1st Saharan territorial group later visited two other military units near the town of Remada.

The visit came amid reports of fresh fighting between forces loyal to Libyan leader Muammar Gaddafi and rebels in the western part of Libya, close to the Tunisian border.  

Falling mortar shells on the Libyan side of the border could be seen and heard in the Tunisian town of Dhiba throughout the night from Wednesday to Thursday, a correspondent of "Radio Mosaique" reported on Thursday morning.

In addition to hundreds of Libyan refugees, representatives of humanitarian associations were also seen entering Tunisia from the Wazen border point early Thursday.