A number of mortar shells have targeted the sprawling US military bases on the outskirts of Tikrit in Iraq's northern province of Salah al-Din.

A local police source told the Aswat al-Iraq news agency that multiple mortar rounds landed Thursday morning inside Camp Anaconda, which is located in the Yathrib district on the southern outskirts of Tikrit.

There has been no word on the number of casualties.

The assault followed an earlier attack on the US military base in Salah al-Din province.

"A mortar shell hit Anaconda base at Yathrib district in southern part of Tikrit early on Wednesday. However, there were no casualties reported," a police official seeking anonymity said.

Camp Anaconda, located about 40 miles (64 km) north of Baghdad, is the main logistics hub for all US bases in war-battered Iraq. The camp is spread over 15 square miles and can house 28,000 military personnel.

Meanwhile, two Katyusha rockets landed Tuesday on Camp Speicher in northern Tikrit, but caused little structural damage.

Camp Speicher is located near Tikrit in northern Iraq and approximately 105 miles (170 km) north of Baghdad. It is named after F/A-18 pilot Michael Scott Speicher who was shot down during the first Persian Gulf War in 1991.