DOHA: Qatar accused Bahrain today of abusing a routine fisheries enforcement case to deepen a three-month diplomatic crisis between the emirate and its Gulf neighbours.

"The State of Qatar condemned the statement issued by the Bahraini interior ministry on the detention of 15 Bahraini boats carrying 20 sailors, describing it as a desperate attempt to escalate the ongoing diplomatic dispute," the official QNA news agency reported.

An interior ministry official said the 15 Bahraini fishing boats seized by the Qatari coastguard, most of them over the past three days, had been operating illegally in the emirate's waters and had been held under routine procedures.

The 20 fishermen on board would be released within the next three days while the courts would decide what happened to the boats.

The official told QNA the Coast and Borders Security Department had repeatedly warned the fishermen not to operate in Qatari waters and not to use harmful fishing practices.

Qatar had a longstanding territorial dispute with Bahrain over the waters and small islands that separate the peninsula from the main islands of its maritime neighbour which was only resolved by the International Court of Justice in 2001.

In June this year, Bahrain joined with Saudi Arabia, the United Arab Emirates and Egypt in breaking off diplomatic relations with Qatar and severing all sea and air links.

The four governments issued a string of demands of the emirate, notably that it follow them in blacklisting the Muslim Brotherhood as a terrorist group and downgrading relations with Iran.

Qatar 's emir, Sheikh Tamim bin Hamad Al-Thani, has held talks in Turkey, Germany and France over the past week to try to find a way out of the crisis and is due to meet US President Donald Trump in New York later on Tuesday.