Tribal forces in Yemen's south-eastern town of Rada'a Friday prevented insurgents linked to al-Qaeda from pressing into the town, reported the Yemeni news website Mareb Press.
The insurgents, commanded by Tariq al-Dahab, had to retreat after clashes with local fighters added the report, quoting local sources.
There were no immediate reports about casualties. Mareb Press quoted the sources as saying that the tribes had also thwarted an attempt by the militants to storm a prison where many al-Qaeda suspects are held in the southern part of the town, dpa reported.
Tribes in Rada'a, 150 kilometres south-east of the capital Sana'a, have set up vigilance groups to protect key institutions in the town, after government forces left the town.
More than 200 armed radicals this week captured army positions and the famous al-Amiriya castle in Rada'a, making it the closest town to Sana'a to be controlled by militants affiliated to al-Qaeda.
Their chief, al-Dahab, is a relative of al-Qaeda's spiritual leader in Yemen, Anwar al-Awlaki, who was killed in a US airstrike last September.
Elsewhere in Yemen, three soldiers were killed in the southern port city of Aden when militants opened fire on their patrol, a security source said.
The militants - believed to be affiliated to al-Qaeda - also threw a bomb at the soldiers' vehicle, which was completely burnt, the state-run 26 September news website quoted the source as saying.
Aden is one of several southern Yemeni cities where militants have been attacking, taking advantage of year-long political turmoil and a weak central government to expand their influence in the country.
The opposition accuses the authorities of complicity with the insurgents, a means of extending President Ali Abdullah Saleh's grip on power.
In November, Saleh signed a Gulf-brokered deal to step down after 33 years in power. Presidential elections are scheduled to be held on February 21.
Saleh has previously portrayed himself as the only one who can fight al-Qaeda insurgents and has used the threat of militants to seek support from the West and extend his stay in power despite months of protests against him.