Pirates attacked five ships over four days in one of the world’s busiest shipping channels, including two separate attempts on Monday, the Straits Times reported.

Just after midnight on Monday, pirates attacked a crude oil tanker in the Singapore Strait. Within two hours of that, there was another attack on a dry bulk carrier. They tied up crew members in both incidents but failed to rob the ships as alarms were triggered on both occasions, the newspaper reported late on Monday.

The ships in question in Monday’s attacks were 105,000 dead weight ton crude oil tanker Bamzi and dry bulk carrier Trust Star. Bamzi loaded from Basrah in Iraq in November and is headed for Qingdao in China, according to Bloomberg tanker tracking data. Trust Star sailed from Gothenburg in Sweden in November and is headed for Huanghua in China, according to the data.

There have been 29 piracy incidents in the Singapore Strait so far in 2019, the Straits Times said. The Regional Cooperation Agreement on Combating Piracy and Armed Robbery against Ships in Asia’s Information Sharing Centre had issued alerts after three piracy attempts in the strait on Dec. 20, it said.

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