Police out in force on the streets of Sanaa.

Security is tight in Yemen's Capital.

Al Qaeda in the Arabian Peninsula is putting a bounty on the U.S. ambassador Gerald Feierstein for anyone who kills him. They are offering three kilograms of gold.

Barriers line the roads

Al Qaeda is also offering to pay more than 20,000 dollars to anyone who kills an American soldier in Yemen.

( SOUNDBITE) (ENGLISH ) ANALYST NASSER ARRABYEE SAYING

"Al-Qaeda now , what al-Qaeda did when it declared that bounty for killing the U.S ambassador means to me that al-Qaeda weak now not strong , but al-Qaeda the same time want to invest this, wanted to exploit in the chaos and the security in Yemen ".

Al Qaeda in the Arabian Peninsula is regarded by the U.S. as the most dangerous branch of the network founded by Osama bin Laden.

Yemen -- a key U.S. ally -- is struggling against challenges on many fronts after mass protests forced veteran leader Ali Abdullah Saleh to step down in February after decades in power.