RAMALLAH, West Bank, Aug 8 (Hamuda Hassan/Reuters) - Palestinian police traded gunfire with unknown assailants at the prime minister's compound in Ramallah on Wednesday, a Reuters witness said, but there were no immediate reports of injuries.

Prime Minister Salam Fayyad was away touring the southern West Bank, near Hebron, at the time.

Palestinian officials declined to comment, citing the sensitivity of the incident, and there was no immediate indication of who was behind the attack.

The exchange of gunfire in the West Bank city lasted around a minute, several witnesses confirmed, and the Palestinian Authority's official news agency, WAFA, said that there had been no casualties.

Fighting had subsided by the time Palestinian special forces arrived, a few minutes after the incident began. Police were deployed in force, scouring the area for shell casings.

The shooting occurred on a main thoroughfare clustered with modern government buildings under constant police guard.

Ramallah is the Palestinians' administrative capital in the West Bank, under limited self-rule by the so-called Palestinian Authority, in territory Israel captured in the 1967 war, and for which Palestinians have long sought statehood.

The Palestinian Authority has launched a security crackdown in the West Bank in recent months, arresting scores of suspects in a security sweep that has sparked anger against President Mahmoud Abbas's Fateh-led government.

The crackdown, led by elite presidential guards and the counter-terrorism unit, is seen as a determined bid by the Western-backed authority to regain control of key areas and smash armed elements that could challenge its power.

Its forces have targeted not only gang leaders and criminal groups, but also rogue security officers suspected of arming and directing them. Fayyad told Reuters in June that the operation would be broad-based and long lasting.

Abbas and Fayyad have brought stability to much of the West Bank in recent years, focusing attention on building up a professional security force.

Western nations and Israel have praised them on this front, but they have riled some faction leaders at home who are eager to maintain their independence and strength. (Writing by Noah Browning; Editing by Michael Roddy)