Israel has targeted at least a dozen Syrian-bound vessels, mostly carrying Iranian oil, since 2019, according to a report on Thursday.

Citing unnamed U.S. and regional officials, The Wall Street Journal said that Israel has “used weaponry including water mines to strike Iranian vessels or those carrying Iranian cargo as they navigate toward Syria in the Red Sea and in other areas of the region.”

Despite U.S. and international sanctions, Iran has continued its oil trade with Damascus, shipping millions of barrels annually to the regime run by Syrian President and Iran ally Bashar Assad. The report said that some of the naval attacks have also targeted Iranian efforts to move other cargo, such as weapons, through the region.

Iran’s Islamic Revolutionary Guards Corps controls Syrian-bound oil cargoes, which are designed to circumvent sanctions and to fund the IRGC, often carry hundreds of millions of dollars worth of oil, said the report.

The Wall Street Journal further reported that Israeli Prime Minister Benjamin Netanyahu’s office referred questions to the Israeli military, which declined to comment on any Israeli role in the attacks on Iranian ships. Iranian officials also did not respond.

The purported maritime attacks on Iranian shipping create a new front in the ongoing campaign by Israel to counter Iran’s entrenchment in Syria and Lebanon. Israel has conducted hundreds of airstrikes, mainly in Syria, against Iranian and Iranian-backed groups.

The report comes amid increasing tensions between Israel and Iran, as well as efforts by the United States to try to restart negotiations with the Islamic Republic over its nuclear program.

Last week, Israel blamed Iran for an explosion that hit the Israeli-owned ship, MV Helios Ray, in the Gulf of Oman. U.S. officials in the past have blamed Iran for attacks on tankers in the Persian Gulf region.