ISLAMABAD, Pakistan – A former president of Afghanistan accused Pakistani military intelligence of trying to kill him in a suicide attack yesterday, intensifying an increasingly bitter row between the two countries.

Sibghatullah Mojaddidi, who is now in charge of a commission to encourage Taliban members to lay down their arms, was wounded in the attack that killed two bombers and two civilians.

Mr. Mojaddidi was being driven to work on a main road in Kabul when the attackers detonated a car laden with explosives near his vehicle.

Shortly after the attack, Mr. Mojaddidi appeared at a news conference with bandages on his hands and blamed a Pakistani military intelligence agency, the Inter Services Intelligence.

“We have got information that ISI of Pakistan has launched a plan to kill me,” Mr. Mujaddidi said.

“What is my fault? My fault is that I am working for the peace and prosperity of Afghanistan,” he added. “[Pakistan’s president, Pervez] Musharraf and ISI of Pakistan do not want Afghanistan to be safe and secure.”

Pakistan’s foreign ministry immediately rejected the charge.A spokesman said: “We condemn such attacks and loss of innocent lives wherever they happen. These are baseless allegations and we reject them completely.”

Mr. Mojaddidi’s accusations of Pakistani involvement in the attack have further inflamed a diplomatic spat be tween the two neighbors, both key American allies in the war on terror, which was sparked by Afghan complaints that Pakistan must do more to curb terrorists who plan and launch attacks from sanctuaries in Pakistan’s borderlands.

Pakistan, which officially ended its support for the Taliban after the September 11, 2001, attacks on America, says that it does all it can to stop cross-border movement by militants.

[Also yesterday, a roadside bomb killed four American troops passing by in an armored vehicle in eastern Afghanistan, the deadliest attack on coalition forces in a month.

In Kabul, a suicide bombing yesterday killed two people and narrowly missed the chief of Afghanistan’s upper house of parliament, and he accused Pakistani intelligence of trying to assassinate him.

The two bombings were the latest in a series of militant attacks that appear to be gathering intensity four years after the ouster of the hard-line Taliban regime by a American-led invasion.

The four American troops died while patrolling in the Pech Valley in Kunar province, military spokesman Colonel Jim Yonts said. Kunar Gov. Asadullah Wafa said the roadside blast went off as a convoy of six American vehicles passed.

Colonel Yonts said attacks would not deter the American-led coalition from their mission of defeating Taliban and Al Qaeda militants and establishing lasting security.]