Authorities searching for the missing Malaysia Airlines plane have widened their search, amid increasing frustration from passengers' families.

Search teams had expanded their scope to the Straits of Malacca, Malaysia Airlines said.

The authorities are looking at a possibility of an attempt made by MH370 to turn back to Subang.

The Beijing-bound flight vanished on Saturday shortly after it left Kuala Lumpur. There were 239 people on board.

The search for the missing Malaysia Airlines plane has entered its fourth day

Authorities are also investigating two men who boarded the missing plane on Italian and Austrian passports stolen in Thailand years ago.

Malaysian police said one of the two had been identified as a 19-year-old Iranian man who they believe was hoping to settle in Germany and was not likely to belong to a terrorist group.

Experts say the presence of two passengers with stolen passports is a breach of security, but is relatively common in the region and could relate to illegal migration.

(Source: BBC)