RAMALLAH Feb 28 (JMCC & Agencies) - Sixteen Palestinians and four policemen were injured as clashes that started Sunday at Jerusalem's holy mosques spread to other areas of the Old City. At least six of the Palestinian injured were struck by rubber-coated bullets fired at protesters by Israeli police, sources said.

Police denied firing rubber-coated bullets.

Waqf officials said that the clashes began when hundreds of foreign tourists and religious Jews sought entry to the mosque area to pray on the holiday of Purim.

This is the first time this has ever happened, said Naji Barakat from inside the Haram al-Sharif to al-Jazeera television. He said that all of the entrances to the mosque compound were closed and guarded by dozens of Israeli police.

Officials were in touch with international missions, warning of the dangerously tense situation, Barakat said.

Answering calls to protect the mosque, tens of Palestinians gathered in its grounds overnight to try to prevent the entry of Israeli worshipers. Israeli police then entered the compound to clear and detain the protesters.

An Israeli police spokesman said Israeli police raided a plaza near the al-Aqsa Mosque in Jerusalem on Sunday in response to stone-throwing protests by Palestinians.

Shmuel Ben-Ruby said police entered the compound when about 20 Palestinians threw stones, but that the protesters had quickly taken cover inside the mosque.

Israeli police do not usually enter the area, other than in response to incidents. Police did not enter the mosque structure.

Dozens of checkpoints had been erected at the entrance to Jerusalem's Old City leading to the mosque compound preventing Muslim worshipers under age 50 from observing the dawn prayer, said the Al-Aqsa Organization for Waqf and Antiquities.

In the existing arrangements at the mosques, Jews are allowed to tour the grounds at select hours without praying. Non-Muslims are not allowed inside the shrines.

These arrangements have been in place since September 2000, when clashes broke out at the site after Israeli politician Ariel Sharon visited the mosque area. Those clashes sparked months of violence from which negotiations between Palestinians and Israelis have yet to recover.

Jews pray at the adjoining Western Wall, believed to be the last remaining wall of an ancient Jewish temple. The visitors entered the mosque compound Sunday from Mugharibeh Gate, which connects the Western Wall with the two mosques, al-Aqsa and the Haram al-Sharif.