KANDAHAR, Afghanistan – Afghan troops clashed with Taliban insurgents attacking a supply convoy for NATO troops, killing nine militants, officials said Saturday, while roadside bombs killed a NATO soldier in a separate convoy and four policemen.

The violence came as Barack Obama arrived in Kabul as part of an official congressional delegation. It was the Democratic presidential contender's first visit to Afghanistan.

The militants were killed after they attacked a supply convoy for NATO-led troops in Zabul province, said provincial police official Jalali Khan. There were no casualties among the Afghan troops, he said.

In neighboring Kandahar province, a blast struck a police patrol in Maywand district, killing four officers and wounding another, said Khan Mohammad, a police official.

Another bomb struck a NATO convoy in Kandahar's Panjwayi district, killing a soldier, NATO's press office in Kabul said. NATO did not release the dead soldier's nationality or say how many were wounded. Most of the troops in the area are Canadian.

Southern Afghanistan is the center of the country's Taliban-led insurgency. More than 2,500 people – mostly militants – have died in insurgency-related violence this year in Afghanistan, according to an Associated Press tally of official figures.

In northwestern Pakistan, at least 10 Taliban died in fierce fighting between two rival militant groups, a government official and Taliban spokesman said Saturday.

Hundreds of supporters of top Pakistani Taliban leader Baitullah Mehsud clashed Friday with a breakaway faction of the group in Mohmand tribal region, said local administrator Syed Ali.

He said both sides used rocket-propelled grenades and other weapons in the fighting, which lasted for several hours. Between 10 and 15 men died, he said.

A spokesman for Mehsud's group, who identified himself as Dr. Asad, claimed they killed 15 militants of the rival group and captured 120, including two commanders whom he said were then tried under Islamic laws and executed after being found guilty of slaying one of their commanders.

Mehsud is the leader of a militant umbrella group, Tehrik-e-Taliban Pakistan, and he has been accused in the assassination of former Prime Minister Benazir Bhutto, which he denies. His supporters are believed responsible for numerous bombings and attacks on security forces in the country's tribal regions and other areas over the past year.

The government led by Bhutto's party – installed after winning Feb. 18 elections – has encouraged peace talks involving Mehsud's group and other militant outfits that has quelled violence.

But Mehsud this week blamed the provincial government in the northwest of Pakistan for recent military operations against militants and threatened to attack it unless it quit by Tuesday. The provincial government, has rejected the demand, saying it only called in troops after Mehsud's men killed 17 Pakistani soldiers near the town of Zargari last week.

Western officials are concerned the easing of Pakistani military pressure on militants has given the Taliban and al-Qaeda more freedom to operate in Pakistan's tribal regions. The U.S. military has reported a spike in cross-border attacks into Afghanistan.

Associated Press writer Riaz Khan contributed to this report from Peshawar, Pakistan.