NAIROBI, Kenya — A nun shot four times at the Somali hospital where she worked forgave her killers as she lay dying, colleagues said yesterday in the wake of her slaying, which has focused attention on Islamic extremism in the Horn of Africa.

Sister Leonella, 65, muttered the words “I forgive, I forgive” in Italian after being shot by gunmen Sunday, the Reverend Maloba Wesonga told the Associated Press at a memorial Mass for the nun in the Kenyan capital, Nairobi.

Her killing was not a random attack and might have been sparked by remarks by Pope Benedict XVI about Muslims that have sparked angry reaction from Muslims around the world, the regional head of the Austrian-funded hospital where Sister Leonella worked, Willy Huber, said.

Sister Leonella, whose birth name was Rosa Sgorbati, had lived and worked in Kenya and Somalia for 38 years, her family said.

She was shot as she left the S.O.S. hospital. Her bodyguard also was slain. The two had been walking the 30 feet from the Mogadishu hospital to the sister’s home, where three other nuns were waiting to have lunch with her.

“She had no chance,” Mr. Huber added. “It was like an execution.”

The deputy leader of the Supreme Islamic Courts Council, Abdurahman Mohamed Farah, said the nun’s killing was unrelated to the pope’s speech, blaming it instead on Somali warlords who lost control of Mogadishu in June after intense fighting with the Islamic militia.

“We will punish the culprits behind this nasty killing,” he told journalists in the capital. One man has already been arrested.

A powerful, militant Islamic group has all but wrested control from the weak and factional Somali government. With it has come a hard-line Taliban-style rule, complete with public floggings and executions. Its leaders have pledged to wage holy war against an African peacekeeping force that is supposed to arrive early next month to help stabilize the country.

In recent months, the Islamic group has extended its control over much of southern Somalia, challenging the weak, U.N.-backed government that has not been able to exert any power outside Baidoa.

The rise of the Islamic militants has coincided with a wave of killings of both foreign workers and moderate Somali intellectuals.

Among them were a Swedish journalist, Martin Adler, who was killed in June during a demonstration in Mogadishu and a prominent Somali peace activist, Abdulkadir Yahya Ali, who was slain a month later. British Broadcasting Corp. journalist Kate Peyton was shot to death last year.

America has accused the Islamic group of sheltering suspects in the 1998 bombings of American embassies in Kenya and Tanzania. Al Qaeda chief Osama bin Laden has portrayed Somalia as a battleground in his war on America.

A regional analyst, Matt Bryden, said a renegade Islamic militia or warlords could be behind the killings, hoping to taint the image of the Islamic Courts.

Sister Leonella was aware of the dangers in Somalia and used to joke that somewhere was a bullet with her name engraved on it. “But this never deterred her or discouraged her,” Rev. Wesonga, who is secretary of the Archdiocese of Nairobi, told the AP at the memorial service.