Singapore, July 20 (Reuters) - Shipping data on Monday showed that the number of vessels passing through the Strait of Hormuz remained low at the start of the week, as the United States and Iran stepped up their attacks in the Middle East.

Data from the London Stock Exchange Group showed that four ships transited the strait on Sunday, compared to eight the previous day. The data also showed that at least three oil product tankers and one very large crude carrier (VLCC) have entered the strait since Friday to load oil.

The London Stock Exchange Group's data covers the traffic of container ships, bulk carriers, vehicle carriers, and oil, gas, and chemical tankers.

On Sunday, the United States announced that it had completed its eighth consecutive night of attacks against Iran, while US allies Kuwait and Bahrain reported further Iranian attacks.

In the past few days, both sides have targeted maritime traffic, with the United States announcing a naval blockade of Iranian ports, while Iran announced it is targeting ships that violate its rules regarding navigation in the Strait of Hormuz, through which a fifth of the world's oil shipments usually pass.

The United Kingdom Maritime Trade Operations (UKMTO) said on Monday it had received a report of a fire on board a vessel eight nautical miles northwest of Khasab in Oman. UKMTO added that the cause of the fire was still under investigation.

No liquefied natural gas tankers have been seen passing through the strait since Thursday. Tankers and other vessels have occasionally switched off their transponders to conceal their passage.

The data showed that only one shipment of liquefied natural gas is known to have left the Gulf during the past week.

However, S&P Global analysts noted in a note that LNG production and ship loadings in Qatar and the UAE continued at a relatively strong pace despite disruptions to outbound shipping, leading to increased LNG stockpiles on waiting tankers within the Gulf.

The memo added, "If the de facto blockade of the Strait of Hormuz eases in the coming weeks, these ships could allow for a relatively rapid increase in exports, enabling the export of liquefied natural gas that has already been produced and loaded."