Somali insurgents fired mortars at a visiting US Congressman today as pirate gangs threatened revenge against the United States for the dramatic rescue of an American hostage yesterday.

The Islamist insurgents targeted Mogadishu airport as an aircraft carrying Donald Payne took off after the first visit to the Somali capital by a senior US politician since 1994.

“One mortar landed at the airport when Payne’s plane was due to fly and five others after he left and no one was hurt,” Abukar Hassan, a police officer at Mogadishu airport, said.

Mr Payne, a veteran New Jersey Democrat who is chairman of the Congressional Black Caucus and head of the House of Representatives subcommittee on Africa, discussed the piracy problem with Sheikh Sharif Sheikh Ahmed, the Somali President.

His one-day visit came the day after US Navy snipers shot dead three Somali pirates who had held Captain Richard Phillips hostage in a lifeboat for five days, rescuing him unharmed.

Bruno Schiemsky, a military analyst who monitors Somalia, said that an American politician such as Mr Payne would have been seen as a prize for hardline Islamists, such as the Shabaab movement, regardless of the clash with the pirates.

“I’m pretty sure they would have targeted him anyway,” he said. “That said, the Shabaab and the other bad guys will spin this in such a way to make it look like they are protecting ordinary Somalis against a common enemy,” he said.

US Navy sharpshooters aboard the USS Bainbridge opened fire on the pirates at dusk on Sunday as the US Navy destroyer towed the lifeboat to quieter waters.

US officials said that the snipers shot the pirates when one of them pointed his AK-47 at Captain Phillips, putting his life in “imminent danger". The snipers took three shots to kill the three pirates from a range of just over 25 yards, officials said.

Captain Phillips, who was taken hostage on Wednesday when the crew of his container ship repulsed a pirate attack, was quickly rescued.

ABC News reported that the US special forces acted when they saw Captain Phillips move to the side of the lifeboat to relieve himself, presenting the opportunity to shoot the pirates without harming him.

The fourth pirate, who was already aboard the USS Bainbridge seeking medical care for a hand wound sustained during the failed attack on the US-flagged Maersk Alabama, was taken into custody.

American authorities were pondering yesterday whether to try the surviving pirate – reported to be as young as 16 – in the United States or to hand him over to Kenya for trial under an agreement reached earlier this year.

An FBI team has gathered evidence from the Maersk Alabama for a criminal trial. If he is taken to the US, he could be tried in a federal court in New York or Washington DC.

Captain Phillips is expected to be reunited with his wife Andrea when he flies back to New York tomorrow. The couple will then return to their farmhouse in Underhill, Vermont.

Angry pirates vowed retaliation for the deaths of their comrades, raising fears for the safety of some 230 foreign sailors still held hostage in more than a dozen ships anchored off the Somali coast.

Abdullahi Lami, one of the pirates holding a Greek ship anchored in the Somali town of Gaan, said: “Every country will be treated the way it treats us. In the future, America will be the one mourning and crying. We will retaliate... the killings of our men.”

Insurance premiums for vessels flying the American flag in the region are expected to soar in the coming days.

President Obama said today that the US was determined to confront the pirates. “We are going to have to continue to work with our partners to prevent future attacks,” he said. “We have to continue to be prepared to confront them when they arise and we have to ensure that those who commit acts of piracy are held accountable for their crimes.”

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