Pakistani troops have abandoned a fort in a remote tribal area, a day after another was overrun by pro-Taleban militants, officials and witnesses say.
They say that paramilitary personnel at Sipla Toi military post in South Waziristan left their positions fearing an attack by the militants.
But an army spokesman told the BBC he had received no such reports.
On Wednesday, the army said hundreds of militants temporarily seized a fort in the Sararogha area of South Waziristan.
Locals told the BBC that 30-40 troops had been stationed at Sipla Toi, some 90km (55 miles) from the town of Dera Ismail Khan. The outpost is nearly as big as the one at Sararogha.
“According to our reports, the troops abandoned the fort on their own. Some left last night, others went away this morning.
“There was no attack from the Taleban,” a South Waziristan tribal administration official based in the town of Tank told the BBC.
A resident of the area said that the retreating troops had not left any weapons or ammunition behind.
A Taleban spokesman, Maulvi Umar, told the BBC Urdu service that militants had captured the Sipla Toi fort. But there was no independent confirmation of his claims.
South Waziristan is a known stronghold of pro-Taleban and al-Qaeda militants.
The region has been at the centre of fighting between the army and militants in recent months.
Correspondents say the militants are now openly challenging the army in the area bordering Afghanistan.