Israeli archaeologists announced Tuesday they have discovered the remains of an early Islamic fortress and Roman-style bathhouse at a dig along the country's southern Mediterranean coastline.

The finds uncovered at the Yavneh-Yam promontory apparently served as part of a string of fortifications against Crusaders invaders, Prof. Moshe Fischer of the Department and the Institute of Archaeology at Tel Aviv University told Xinhua.

Both the fortress and the bathhouse are from the Early Islamic period (8th-12th centuries CE) and were part of the Islamic defensive system against the crusaders that had taken Jerusalem and the port city of Jaffa, Fischer said.

Yavneh-Yam was an important port town during the early Islamic period and it served as a port for inland settlements almost without interruption between the Bronze Age (mid-2nd millennium BCE) and the Middle Ages.

"This fortification was linked with other similar constructions around the coast to protect the area, and served as defense from the crusaders," Fischer said, adding that the finds was "very important because it can provide us with more information about the beginning of the crusade."

The excavations, which began in 1992, revealed public buildings, bathhouses, residential villas, workshops and storerooms belonging to the Hasmonean, Hellenic, Byzantine, and Islamic periods.

"This finds confirm the uninterrupted use of the Yavneh-Yam harbor throughout the history," Fischer said.

"We just recently started excavating inside the promontory," he said, "and in only four weeks of work we excavated the fortress and the bathhouse. We are very excited because we are sure that we will find more as we dig deeper in the 15-meter high promontory. Up to now, we have only dug two meters."

Fischer believed that the artifacts they would find as they excavate will be of great importance in helping understand more about the early Islamic era and the crusader period.

"We expect to find engraved coins, glass, everyday objects, but more important of all will be the inscriptions that can provide us with more information about that period," he said.

The archaeologist pointed out that the discovery of the Roman- style bathhouse was a surprise for the whole team.

"The bathhouse is important because it follows Roman principles with double-floor levels providing the bathers with hot air," Fischer said.

"The only difference is that the upper floor of a regular Roman bathhouse is made of brick to endure the high temperatures, while that of the Islamic one is made of local soft lime stone, which gets destroyed after a short period of use."

The estimated size of the fortress, which has not yet been dug out entirely, is about 70 square meters, while the bathhouse is only 10 square meters.