Pakistan law enforcement agencies went on indefinite red alert, bomb-sniffing dogs checked parks and security was tightened Monday at foreign embassies on the fifth anniversary of the Sept. 11 attacks, a senior official said.

"Law enforcement agencies are on red alert," Brig. Javed Iqbal Cheema, head of counterterrorism at Pakistan's Interior Ministry, said. He declined to elaborate.

Get complete coverage of the fifth anniversary of 9/11 in FOXNews.com's special Sept. 11 Center.

A report in Monday's Daily Times newspaper said that intelligence agencies had received information that militants or their supporters would try to "exploit the situation" by stepping up their "nefarious designs."

Cheema said his agency had not received a specific threat, but added, "This thing with anniversaries — one has to take precautions."

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The newspaper report said security was heightened at airports, foreign embassies, diplomats' residences and army bases.

Police were prepared to strictly enforce a law against unauthorized public gatherings, the report said, quoting various authorities.

It also said police were closely watching train and bus stations to prevent attempted terrorist attacks.

Cheema declined to give many details about operations or confirm the newspaper report. "We've taken all possible precautionary measures," he said.

Bomb-sniffing dogs combed parks and other public places in the capital, Islamabad, Cheema said.

Asked how long law enforcement agencies would be on heightened alert, he said, "We don't have a deadline for this. Let's see."

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