PESHAWAR - Two political workers of an independent candidate were killed and three others sustained injuries when unidentified gunmen attacked their vehicle in Dera Ismail Khan.

According to details, when campaigners for an independent candidate Abdul Rahim Burki, who is contesting from NA-42 South Waziristan Agency, were on way in a car to their election office in Paharipur.

Police officials said that Abdul Rahim was not in the car when it was attacked in Islampur area. Due to indiscriminate firing of the assailiants, the driver lost control over the vehicle and it collided with a tree.

Mula Dad and Jan Gul died while three others got injured and were shifted to the Dera Ismail Khan District Headquarters Hospital. The assailants escaped after committing the crime.

Agencies add: The attackers ambushed a car carrying workers of independent candidate Abdul Rahim Burki in Dera Ismail Khan, close to the lawless tribal area, police chief Khalid Sohail said. Taliban militants have vowed to target secular parties running in the May 11 general elections.

"The assailants opened fire on the car, its driver lost control and the vehicle hit a roadside tree," Sohail told AFP. "Two workers were killed and three wounded," he said, adding that the gunmen fled on a motorbike.

Another police official confirmed the attack and the fatalities and said the injured workers were out of danger. There are fears that militant violence will mar the national and regional elections on May 11, which will mark the country's first democratic transition of power after a civilian government has served a full term in office.

Burki is contesting a seat in South Waziristan tribal district, which is under military control. Most of the population fled after a military operation expelled Taliban and Al-Qaeda linked militants.

He told AFP that more than 80 percent of his voters were living in Dera Ismail Khan and nearby Tank districts, though their votes will count in the South Waziristan constituency. Burki said the car was clearly identified as connected to his campaign but he had no idea who the attackers were.

"This is my first election. I have no party affiliation and I received no threats from any group so far," he told AFP. "It appears they had been waiting to target the vehicle."

There was no immediate claim of responsibility, but the umbrella Taliban faction Tehreek-e-Taliban Pakistan said it was behind two attacks on Sunday and the killing of a candidate for outgoing coalition partner the Muttahida Qaumi Movement (MQM), the first to die in the election campaign, on Thursday.