An American UN official who was kidnapped two months ago in southwestern Pakistan was released after Pakistani authorities freed several separatists held by the security services for the past few years, The Times has learnt.

John Solecki, the head of the UN refugee agency’s office in the southwestern province of Baluchistan, was found on Saturday night by the side of a road near Quetta, the provincial capital, with his hands and feet bound, pleading: “Help me, help me!”

Ethnic Baluch separatists had earlier claimed responsibility for the abduction and at one point threatened to kill Mr Solecki — the highest-profile Westerner to be kidnapped in Pakistan since Daniel Pearl, the Wall Street Journal reporter who was beheaded in 2002. News of Mr Solecki’s release came as a suicide bomber attacked a crowded Shia mosque in central Pakistan, killing at least 28 people.

Shakil Baloch, a spokesman for the Baluch Liberation United Front (BLUF), one of several separatist groups fighting for greater autonomy in Pakistan, told local journalists that Mr Solecki was released on humanitarian grounds. “We want to give a message to the international community that Baluch are not terrorist,” he said.

Rehman Malik, the federal Interior Minister, said that Mr Solecki was freed because of personal intervention by President Zardari. Some sources in the Government said that his release was agreed in negotiations with the BLUF involving Pakistani and US officials. “There was certainly a trade- off,” one official said.

The BLUF, which is fighting for greater autonomy for Baluchistan, had been demanding the release of Zarina Baloch, a women’s rights activist, and several others being held by security forces. Human rights groups say hundreds of Baluch nationalists have been detained without trial since security forces killed Akbar Bugti, a former governor of Baluchistan and nationalist leader, in 2005.

The Government has already freed some of the detainees that the BLUF wants released, and has promised to find out about others. It is not clear whether those released included Ms Baloch, who rights activists say was taken away by security forces a few years ago and was also allegedly raped, although the Government denies detaining her.

Harbiar Marri, a Baluch separatist leader now living in London, is also believed to have played a significant role in securing Mr Solecki’s release. The Pakistani Government has sought the extradition of Mr Marri, whose brother, Balach Marri, lead the insurgency in Baluchistan and was killed by security forces two years ago.

Baloch provincial and UN officials declined to comment on the reasons for Mr Solecki’s release.

Jennifer Pagonis, a UN spokesman, said only that he was flown to the United States by special medical flight early yesterday morning after spending the night in a military hospital in Quetta. “He seemed OK this morning,” Ms Pagonis said.

Ban Ki Moon, the UN Secretary-General, said that he was grateful for the efforts to secure Mr Solecki’s release, citing Mr Zardari and President Karzai of Afghanistan.

His release was a rare piece of good news in Pakistan, which has suffered a wave of kidnappings, bombings and commando-style attacks in the past year, mostly blamed on Islamic militants based in northwestern Pakistan.

The militants apparently struck again yesterday when a suicide bomber blew himself up at a crowded Shia mosque in the town of Chakwal, central Pakistan, killing at least 28 people and wounding more than 50.

A senior police officer said that the bomber, believed to be in his teens, detonated his explosive after he was stopped by security guards at the entrance of the mosque, where 2,000 worshippers were gathered. “The casualties would have been much higher had the bomber not been intercepted at the entrance,” said Zulfikar Chaudhry, the local police chief.

Witnesses said that the blast occurred during a brief interval in the religious session when the worshipers were going in and out of the mosque.

“There was a huge blast and a lot of smoke. I rushed to the main gate and saw several bodies lying in a pool of blood and body parts scattered all around,” said Qazi Wafa, who was inside the mosque.

It was the first such incident in Chakwal district, in central Punjab province, which is the main recruiting ground for the Pakistani Army. The attack came hours after another suicide bombing killed eight paramilitary soldiers at a security post in Islamabad, the capital.

Hakimullah Mehsud, a deputy to the top Taleban commander Baitullah Mehsud, said that his group was responsible for that attack. Mehsud has claimed responsibility for a raid on a police training school in Lahore that killed 13 people last week.

Yesterday’s attack also followed a bombing late last month on a packed mosque near the Afghan border which killed at least 48 people in the worst attack in Pakistan this year.

Meanwhile, Pakistani troops backed by helicopter gunships and jets killed at least 18 militants in Mohmand, one of seven lawless tribal districts in northwestern Pakistan where Taleban and al-Qaeda militants are sheltering.

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