PESHAWAR: At least seven soldiers and 22 militants died in clashes between Pakistani troops and militants in the restive northwestern tribal belt over the past 24 hours, officials said Saturday.

Security forces carried out a search operation in South Waziristan region and killed 12 militants, a military official said.

He said the operation was launched early on Saturday in Shin Warsak area near the region's main town of Wana following a tip off from intelligence sources that some militants were hiding in the area.

“During an exchange of fire 12 militants were killed and four soldiers embraced martyrdom,” he said.

Another official in Peshawar, the main city in the Khyber Pakhtunkhwa province confirmed the clash, saying “the sting operation is now over.” The Pakistani military in 2009 carried out a sweeping offensive into parts of South Waziristan in order to disable the headquarters of the country's main Taliban faction.

Many of the Taliban commanders and their foot soldiers are believed to have fled into the neighbouring district of North Waziristan, where Pakistan has so far resisted American pressure for a similar offensive.

The search operation in South Waziristan follows an increase in militant bomb attacks in the northwest.

Earlier three soldiers and more than 10 militants were killed after dozens of Taliban militants stormed a check post in a tribal region near the Afghan border overnight.

The attack took place at a check post in Khadizai area on the outskirts of Kalaya, the main town in the lawless Orakzai district, a senior military officer said.

Independent confirmation of the death toll was not immediately possible as the lawless tribal region is barred for journalists.

Khadizai is located in Upper Orakzai most of which is in Taliban hands and is the scene of frequent clashes between security forces and militants while government troops are in control of its lower reaches.

Pakistan's seven tribal districts near the Afghan border are rife with homegrown insurgents and are strongholds of Taliban and al Qaeda operatives.

Militants have killed more than 4,900 people across Pakistan since government troops raided an extremist mosque in Islamabad in July 2007.

Pakistan has for years battled homegrown insurgents in the tribal belt on the Afghan border. It says some 3,000 Pakistani soldiers have also lost their lives in attacks since 2001 when the country joined the war on terror.