Bangladesh police have arrested a senior official from the main opposition party and accused him of plotting against the state following his meeting with an Israeli political adviser, an official said on Monday.

Prime Minister Sheikh Hasina’s government is stepping up a crackdown on political opponents in Muslim-majority Bangladesh, which is also reeling from a wave of killings blamed on Islamists.

Bangladesh Nationalist Party (BNP) joint secretary general Aslam Chowdhury was arrested on Sunday after local media reported that he had met an Israeli government adviser in India in March.

“We’ve arrested Chowdhury for allegedly plotting conspiracies against the government by personally meeting an Israeli politician abroad,” detective police commissioner Abdul Baten told reporters.

Dhaka police spokesman Maruf Hossain Sorder said officers were preparing to file a criminal case against him.

Chowdhury, a successful businessman from the southern city of Chittagong, has denied plotting against the government, telling reporters he met the adviser during a “personal business trip” to India.

Bangladesh has no diplomatic ties with Israel and Bangladeshis are banned from travelling to the country.

The arrest is the latest against the BNP. Party supremo and former prime minister Khaleda Zia was last week charged with masterminding arson attacks during anti-government protests last year, the latest in a string of charges which she says are politically motivated.

Bangladesh has been hit by a political crisis since the BNP and other opposition parties boycotted the general election in 2014.

Scores of people were killed in firebomb attacks on vehicles last year when Zia called a transport blockade as part of her efforts to force the government to hold fresh elections.

Hasina’s secular government launched a crackdown in response to the violence, with thousands of opposition supporters arrested—particularly those from the main Islamist party.

Bangladesh has also been hit by a series of gruesome murders of secular and liberal activists and members of religious minorities.