Danish shipping giant Maersk posted a huge drop in net profit for the first quarter on Thursday as Yemeni rebel attacks are forcing it to avoid the vital Red Sea route.

Maersk reported a net profit of $177 million in the first three months of the year, a 13-fold drop from the same period last year.

Turnover fell 13 percent to $12.4 billion, slightly lower than forecast by analysts surveyed by financial data firm FactSet.

The company, however, raised its outlook for the full year, citing higher demand and increased rates and costs due to the supply chain disruptions in the Red Sea.

It now expects an underlying core profit ranging between $4 billion and $6 billion, up from $1 billion-$6 billion previously.

"We had a positive start to the year with a first quarter developing precisely as we expected," Maersk chief executive Vincent Clerc said in a statement.

"Demand is trending towards the higher end of our market growth guidance and conditions in the Red Sea remain entrenched," he said.

"This not only supported a recovery in the first quarter compared to the previous quarter, but also provide an improved outlook for the coming quarters, as we now expect these conditions to stay with us for most of the year."

Iran-backed Huthi rebels, who control the Yemeni capital Sanaa and much of the country's Red Sea coast, have launched dozens of attacks on ships since November, claiming solidarity with Palestinians caught up in the Israel-Hamas war.

The United States in December announced a maritime security initiative to protect Red Sea shipping from the attacks, which have forced commercial vessels to divert from the route that normally carries 12 percent of global trade.