Taliban militants fighting to oust Afghan government and evict U.S.-led forces from the post-Taliban country have escalated their attacks as the date for Afghan presidential election is drawing closer.

The militants in a string of attacks during the past week have killed at least over a dozen troopers including four U.S. soldiers in Afghanistan.

Only Wednesday, a car suicide blast against the military convoy of international forces in the southern Ghazni province wounded at least two soldiers while killing two civilians.

This incident, according to Ghazni's provincial police Chief Khyal Baz Shizai, occurred in Gilan district at 06:00 p.m.(1330 GMT) wounding two foreign soldiers.

He did not disclose the nationality of the victims but troops from U.S. and Poland have been serving in Ghazni within the framework of NATO-led peacekeeping force ISAF.

Zabihullah Mujahid who claims to speak for the Taliban outfit, in talks with media from undisclosed location claimed responsibility for the attack, said 10 foreign soldiers were killed and two tanks were destroyed, a claim utterly rejected by Shirzai.

More than 113 foreign forces have been killed in Afghanistan since January this year with 22 of them only in May.

The car bomb blast followed similar attack against the NATO-led International Security Assistance Force (ISAF) Tuesday morning in Kapisa province 80 km north of capital city Kabul, killing three American soldiers and wounding another.

Another attack against international troops on Kabul-Bagram highway outside capital city left at least one U.S. service member and another U.S. citizen dead.

A purported Taliban spokesman Zabihullah Mujahid claimed responsibility, saying the insurgents inflicted heavy losses on American forces.

Three unmanned aircraft have crashed and three cases of emergency landing of military helicopters have been reported so far this month and the insurgents have claimed of responsibility for shooting down the planes, while international troops denied.

As the insurgency and counter-insurgency are growing, Afghan and international forces killed over a dozen suspected Taliban fighters in Logar province 60km south of Kabul Tuesday, a press release of the troops said Wednesday.

"The Afghan-led force was clearing a compound Tuesday to disrupt enemy activities when they observed several small groups of armed men moving toward them. The combined force called in a precision air strike, which killed four militants," a press release of U.S. military said Wednesday.

According to the press release, nine more rebels were killed in separate operation in Logar province on the same day Tuesday.

Clashes between security forces and militants have claimed the lives of over 300 people mostly Taliban and nearly a dozen foreign soldiers over the past one month, according to officials.

However, ISAF officials predicted that the peak of violence this year in Afghanistan has not come yet as Taliban rebels are preparing all kinds of attacks against the presidential elections in August.

German Brigadier General Franz Reinhard Golks, in an interview early this week, said that the substantially rising number of militant attacks and skirmishes arose from the rising number of foreign and Afghan soldiers deployed in the country.

Nevertheless, Golks noted that the Taliban would not succeed in bringing about a "total collapse" of the presidential election as he believed the situation in Afghanistan was developing in the right direction.

As part of new tactic to exert pressure on government and U.S.-led forces, the militias have largely relied on suicide attacks and roadside bombings which often claim civilians' lives.

Over the period, the militants attempted on life of President Hamid Karzai's younger brother Ahmad Wali Karzai killing his one of his bodyguards but he himself escaped unhurt.

In the regards, Afghan Interior Ministry Wednesday announced to ensure the security for every presidential candidates by providing20 policemen for each.

Besides, if the candidates prefer to have their own bodyguards, professional training, uniforms and weapons would also be offered by the Ministry.

According to military observers, it is very difficult to check suicide bombers and the militants have vowed to go ahead with the deadly tactics.

Taliban-link insurgency and conflicts had left over 5,000 people with nearly 2,200 of them civilians dead in 2008, while Taliban leadership has vowed to further intensify attacks this year in Afghanistan.

Source: Xinhua