July 23 (Reuters) - U.S. President Donald Trump has threatened to attack a site linked to Iran's nuclear programme known as Pickaxe Mountain, a fortified facility buried deep underground near one of Tehran's main nuclear sites.

The threat reflects escalating tensions as Tehran and Washington trade fire in the Gulf, setting back efforts to end the conflict.

Here is what we know about Pickaxe Mountain:

WHAT IS PICKAXE MOUNTAIN?

Pickaxe Mountain is located 220 km (140 miles) south of Tehran and 2 km (1.2 miles) from the Natanz nuclear complex.

Israeli far-right National Security Minister Itamar Ben Gvir led hundreds of Israeli Jews into Jerusalem's Al-Aqsa mosque compound on Thursday, breaching the site's decades-old status quo as he marked a Jewish day of mourning.

The visit coincided with Tisha B'Av, the Jewish fasting day commemorating the destruction of the First and Second Temples, which is being observed from Wednesday night through Thursday this year.

JERUSALEM, July 23 (Reuters) - Israeli far-right police minister Itamar Ben-Gvir visited the flashpoint Al-Aqsa Mosque compound in Jerusalem on Thursday, praising Jewish visitors he said had prayed at the site in breach of arrangements that allow only Muslim prayer there.

His visit drew condemnation from Jordan and Palestinian officials.

The compound in Jerusalem's walled Old City is one of the most sensitive sites in the Middle East. Known to Jews as Temple Mount, it is ​the most sacred site in Judaism and is Islam's third-holiest site.

By Kanishka Singh

WASHINGTON, July 22 (Reuters) - The U.S. military said on Wednesday it completed its latest round of strikes on Iran at President Donald Trump's direction, for a 12th successive night of American attacks.

Here are details and quotes:

• "U.S. forces struck Iranian military targets including maritime capabilities, missile and drone storage facilities, coastal surveillance sites, and air defense assets," the U.S. Central Command said in a statement.

MANILA, July 23 (Reuters) - U.S. Secretary of State Marco Rubiosaid on Thursday that the United States remains prepared to play a "constructive role" in helping bring an end to the war in Ukraine, following talks with Russian Foreign Minister Sergei Lavrov on the sidelines of an ASEAN gatheringin Manila.

Here are the main events related to the war in the Middle East:

- Iran blasts Trump assets threat -

Tehran said Friday that US President Donald Trump's threat to pay for shipping damage with Iranian assets was an "incendiary precedent".

Trump had said that Washington would start using frozen Iranian assets "that the United States has in its possession, and controls" to pay for "any and all damages done to Ships, Cargo or anything related" in the region.

By Enas Alashray and Yomna Ehab

CAIRO, July 23 (Reuters) - Yemen's Houthi militia attacked two Saudi Arabian oil tankers in a military operation, the group said on Thursday, and a Saudi news agency later confirmed one of the two vessels was ablaze after an assault while sailing in the Red Sea.

The Saudi Arabian state news agency SPA, citing an official source at the General Transport Authority, said an attack caused a fire on the bow of the tanker Encelia but all crew members were safe. SPA did not say who had targeted the vessel.

By Steven Scheer

JERUSALEM, July 23 (Reuters) - A deal between the United States and Saudi Arabia allowing the kingdom to build nuclear reactors using American technology and to enrich uranium has fuelled fears in Israel of the start of an arms race in the Middle East.

The agreement, which still needs Congressional approval, that was announced on Wednesday is meant to allow the Saudis to develop a civilian nuclear programme.