Jakarta. Rupiah extended its losses against the US dollar on Thursday as escalating geopolitical tensions in the Middle East boosted demand for safe-haven assets, while investors also awaited key US labor market data.

The rupiah closed down 19 points at Rp 17,936 per US dollar, compared with Rp 17,920 at the previous close.

Traze Andalan Futures Director Ibrahim Assuaibi said the currency came under pressure after Yemen's Houthi militants claimed attacks on two Saudi oil tankers in the Red Sea, heightening concerns over disruptions to one of the world's busiest energy shipping routes.

"The latest incident follows earlier warnings this week that the group would seek to block Saudi-linked shipping through the Bab el-Mandeb Strait, one of the world's busiest energy transit chokepoints connecting the Red Sea and the Gulf of Aden. Prolonged disruptions could force oil tankers to reroute around southern Africa, extending shipping times and driving up transportation costs," Ibrahim said in a statement on Thursday.

He added that uncertainty intensified after the US military completed a fresh wave of strikes on Iran, marking its 12th consecutive night of attacks and raising concerns over shipping through the Strait of Hormuz.

The rupiah also remained under pressure as investors awaited the release of US initial jobless claims data for the week ended July 18, which could offer further clues on the Federal Reserve's policy outlook.

Domestically, sentiment was dampened after Bank Indonesia kept its benchmark interest rate unchanged at 5.75%.

As of 3:59 p.m. Jakarta time, Bloomberg data showed the rupiah trading at Rp 13,895 per Singapore dollar, Rp 109.81 per Japanese yen, Rp 12,557 per Australian dollar, and Rp 20,474 per euro.