The U.S. government, alarmed at Somali militants' use of Twitter to court followers in the West, reportedly is considering ways of combating the messages.

Measures under review include going as far as shutting down al-Shabaab's Twitter account, the New York Times reported, citing unnamed American officials who are "looking closely" at the terror group's posts.

Recent Twitter posts have targeted the Kenyan military, which has stepped up its efforts against the Al Qada-linked al-Shabaab. "Your inexperienced boys flee from confrontation & flinch in the face of death," al-Shabaab said in one post noted by the New York Times.

Most of the messages are in English, suggesting the intended audience is in the West. The group has been known to recruit members from Somali-American communities in the United States, notably in Minnesota.

It's Twitter account, @HSMPress, had more than 4,600 followers as of Monday night. "Harakat Al-Shabaab Al Mujahideen is an Islamic movement that governs South & Cen. Somalia & part of the global struggle towards the revival of Islamic Khilaafa," the account says.

There is growing evidence that al-Shabaab, is becoming more of a regional terrorist player, with the potential to go global as it targets U.S. citizens and interests.

"We have been getting threats from al-Shabaab against Americans and Westerners," Secretary of State Hillary Clinton said in a TV interview this fall when asked about a decision to warn Americans in Kenya of an imminent terrorist threat. "So it's a very dangerous, uncertain situation. And we want to be sure that whatever information we have, we immediately present to Americans who live, work or may be visiting in Kenya."

U.S. officials have consistently warned that the Al Qaeda affiliate has been adept at recruiting Western Europeans and Americans by playing off their allegiance to their native country.

Nearly two dozen Americans of Somali descent have disappeared into the al-Shabaab camps since 2007. In October, two Minneapolis women who claimed they were helping the poor were convicted of providing money to the terrorist group.

And Minneapolis native Shirwa Ahmed was the first documented case of an American suicide bomber when he blew himself up as part of al-Shabaab operation in Northern Somalia in late 2007.

The Associated Press contributed to this report.