Thirteen people were sentenced to jail by a Saudi court Tuesday for planning an attack against U.S. forces in the Middle East, Agence France-Presse, or AFP, reported. The accused, who were handed down prison sentences ranging from 18 months to 30 years, were convicted of "forming a terrorist cell."

A special terrorism court reportedly jailed about 11 Saudi people for between 18 months and 25 years, while those hailing from Qatar received a sentence of 30 years. At least one person, an Afghan national, was reportedly jailed for five years. The people sentenced were reportedly among 41 others who allegedly belonged to an al Qaeda terrorist cell.

The latest convictions come as Qatar and Saudi Arabia have joined several other nations in the U.S.-led airstrikes against the Islamic State group in Syria.

The terrorist cell reportedly planned to carry out an attack against U.S. forces in Qatar with the help of rockets, grenades and other weapons, AFP reported, citing Saudi Press Agency, or SPA. They also reportedly had plans to attack American forces in Kuwait.

The group also intended to send some of its members to Iraq to learn to make vehicle bombs that could be used to target foreign soldiers, AFP reported, citing SPA. However, it was not clear when the group planned to carry out the attack on American forces, AFP reported.

In 2011, specialized tribunals had been established by authorities to try people from Saudi Arabia and other foreigners accused of being linked to al Qaeda or being involved in attacks that occurred between 2003 and 2006.