Turkish officials say the number of foreign visitors has declined by nearly 30 percent in April amid security concerns and strained ties with Russia.

Tourism Ministry figures released on Friday showed that 1.75 million foreigners had arrived in Turkey last month, down from 2.43 million visitors recorded in April 2015.

The trend is a worrying development for the country's economy, which relies heavily on tourism revenues.

Turkey, a neighbor of Syria, has been hit by a series of deadly suicide bombings — including two that targeted tourists in Istanbul — and is locked in renewed conflict with Kurdish militants in the southeast of the country.

A row with Moscow over Turkey's downing of a Russian plane in November has also resulted in fewer visitors from Russia.