Two men have been arrested after they climbed the 525-foot tower of the eastern span of the Bay Bridge in San Francisco.

California Highway Patrol said they began to receive calls from concerned members of the public at 3pm on Sunday.

The men, aged 18 and 23, used a bike path on the bridge to access a suspension cable, which led to the top of one of the structure's towers, CHP spokesman Vu Williams said.

Two men have been arrested after they climbed the new 525-foot eastern tower of the Bay Bridge in San Francisco

Officers arrived as the pair were making their descent and arrested the men when they returned to the deck of the bridge.

Neither man has been identified, but they have both been booked into San Francisco County jail on suspicion of trespassing, NBC reported.

It is not known why the two men attempted the dangerous climb to the top of one of the towers of the eastern span.

The bridge, officially known as the San Francisco-Oakland Bridge was opened in 1936 after three years of construction.

In 2013 the eastern span of the bridge was replaced as it was considered too expensive to retrofit like the western section.

A ship named the Cosco Busan hit the bridge in 2007 and caused an oil spill in the Bay area, prompting fears over contamination.