LAHORE—Pakistan police claimed Monday to have arrested six suspects, including a would-be suicide bomber, who were plotting to attack a five-star hotel and kill Americans.

Police recovered an explosive-laden suicide vest fitted with 26 hand grenades during the operation in Lahore, the country's second-biggest city, senior police superintendent Zulfikar Hameed told a news conference.

Police in Pakistan, which is under huge US pressure to do more to root out Islamist militants, routinely claim to foil high-profile attacks, most often in Karachi, but rarely release any details of the alleged plots.

It is not possible to confirm the alleged plots independently.

The six suspects were paraded at the news conference wearing black masks to hide their identity.

"Their target was Lahore's Pearl Continental Hotel where some Americans were staying," Hameed said. "They wanted large-scale death and devastation."

"Five terrorists were assigned to explode hand grenades and amid expected panic in the hotel, the suicide bomber was to blow himself up," he said.

Police said the six were trained in Pakistan's northwest tribal district of Khyber on the Afghan border and were captured following a tip-off.

Hameed did not say when and how they were arrested.

Police officer Waris Bhurwana, who was involved in the arrests, said police set up a checkpoint on the main highway from Peshawar in the northwest and intercepted a small Suzuki car outside the eastern city of Lahore last week.

"There were four people in the car, including a would-be suicide bomber," he said, describing the would-be bomber as 15 to 16 years old.

Police recovered four hand grenades, five detonators and a jacket fitted with another 26 hand grenades. Two more suspects carrying hand grenades and following the Suzuki on a motorbike were also arrested, he said.

Police also recovered four kilograms (nine pounds) of hashish, he added.

But officers angrily called a swift end to the news conference after a television reporter snatched away a hood, unmasking one of the suspects.

"If you behave like this we will not invite media in the future," one police inspector said.