By Saud Mehsud
DERA ISMAIL KHAN, Pakistan (Reuters) - Pakistan police said three officers were killed on Friday near the northwestern Afghan border during a gun battle that also killed three militants, in an uptick in violence raising security concerns ahead of national elections early next year.
The attack came within two days of another such militant attack in the region which killed 23 Pakistani soldiers in Dera Ismail Khan district, near the country's lawless tribal districts bordering Afghanistan.
Friday's attack occurred in adjacent Tank district when one of several militants first exploded himself at the main entrance of a police office and residence block and the others stormed in, said police official Iftikhar Shah.
"Our force on guard engaged them in a gun battle for hours," and two more police officers were wounded, he said.
Provincial police chief Akhtar Hayat said three of the attackers were killed. "We are searching for the rest of them, including two who suffered wounds," he said.
A little known militant group that identified itself as Ansar-ul-Islam claimed responsibility, saying it was their first attack, according to a statement sent to a Reuters reporter.
The police didn't verify the authenticity of the claim.
The Pakistani military has conducted several operations against the militants, especially in Waziristan region next to the district where the latest attacks occurred, which once served as a headquarters of the local and foreign Islamist militants.
The militants have ramped up their attacks since they revoked a ceasefire with the government last year.
It is not clear whether the new branch is part of the main Tehreek-e-Taliban Pakistan (TTP) group, which is an umbrella of several Islamist and sectarian outfits.
The TTP has been waging a war against the state for years, seeking to overthrow the government and replace it with a harsh brand of Islamic governance.