Baghdad - Kidnappers released an Egyptian diplomat on Monday, in a dramatic twist to Iraq's hostage crisis, as two Jordanians were snatched and two Pakistanis threatened with death, and attacks claimed 10 lives.

The envoy, Mohamed Mamdouh Kotb, the first diplomat seized in the frenzied abduction-taking that has dogged Iraq for months, was released because of his character and religious faith, the father of three was told by his captors.

"I am free and already at the Egyptian interests section in Baghdad," Kotb, the third ranking diplomat at the Egyptian mission, said.

"I thank God and all those who worked for my release here in Iraq and Egypt."

Just minutes before, the Arab news channel al-Jazeera broadcast a video apparently showing him being freed and even hugging one of his kidnappers.

Al-Jazeera quoted one of the armed militants as saying the envoy was freed "because of the religious faith and the moral qualities he possesses".

Egyptian Foreign Minister Ahmed Abul Gheit thanked the Iraqi people for helping to secure the happy outcome.

Meanwhile, four people were killed, including a child, when a suicide bomber targeted a major United States base in the main northern city of Mosul, blowing up a Chevrolet Caprice, the US military said.

"A car loaded with explosives detonated 50m from the main gate of the Mosul airfield," it said. Three US soldiers and two security guards were also wounded.

In Baghdad, Colonel Mussab al-Awadi, who co-ordinated security arrangements with tribal elders, was the latest victim in a string of killings of senior civil servants since the caretaker government was sworn in on June 1.

His driver and bodyguard were also killed in the attack.

In the main southern city of Basra, two cleaning ladies at the British-controlled airport were shot dead in yet another attack on Iraqis working with the foreign troops still stationed across the country.

And General Nadhem Sharif, police commander on the Iranian border at Mondhiriyah, said one of his guards was killed when insurgents tried to assassinate him.

Yet despite Kotb's release, more than 20 captives are known to be missing or held for ransom, in Iraq's perilous hostage drama buoyed by the snatching of two Jordanian drivers employed by a company supplying the US army.

A colleague at Daoud and Partners named the victims as Ahmed Salameh Hassan and Fayez Saad al-Adwan. The firm has been transporting food to US troops in Iraq since the March 2003 invasion and is headed by an American.

The so-called Islamic Army also threatened to kill two Pakistanis and an Iraqi hostage in a statement broadcast on Al-Jazeera.

A flood of similar threats against scores of foreigners broadcast on Arab television stations has plagued the interim government during its first month in power since the formal winding up of the US-led occupation.

Video footage was shown of the Pakistanis' photo-identity cards, which named them as Azad Hussein Khan and Sajjad Naeem, employed by a Kuwaiti company.

Islamabad appealed to the group to free the two Pakistanis, saying they had nothing to do with international politics.

One sobbing mother was desperate. "My son was the breadearner for three families and they cannot survive without him."

But there was new hope for three Indians, three Kenyans and an Egyptian snatched last Wednesday, after their kidnappers stayed a threat to start killing them, to allow negotiations to take place.

The kidnappers have demanded that the Kuwait contracting firm which employed the truckers halt its operations in Iraq.

Kenya said it has sent two diplomats to Kuwait to negotiate the Kenyans' release, while the 11th-hour reprieve brought cheers from the families of the kidnapped Indians.

"This is good news. Very good news. The entire village prayed today and we shall continue," said Ram Dass, great uncle of one hostage.

New Delhi reiterated assurances of a speedy resolution.

On the political front, defence minister Hazem al-Shaalan lashed out at Iran as Baghdad's "first enemy" and accused the Islamic republic of sending spies and saboteurs into Iraq in an interview with the Washington Post.

Iran and Iraq were at war from 1980 to 1988 in a conflict that left a million dead on both sides.

The United States also confirmed it had granted protected status to nearly 4 000 members of the People's Mujahedeen, Iran's main armed opposition group, now confined to a military-run camp in Iraq, despite a warning from Tehran.