Oil prices were barely changed on Tuesday with markets showing little impact from the bombing attacks in Brussels that killed around 35 people.US benchmark West Texas Intermediate (WTI) for delivery in May was down seven cents at US$41.45 a barrel. Brent North Sea crude for May delivery added 25 cents to US$41.79 a barrel.Analysts said the tendency of such attacks to dampen economic activity could put some downward pressure on crude prices, especially because the Brussels Zaventem Airport was one of the two targets of the bombings, claimed by the Islamic State group.‘What we’ve seen in the past with these terror attacks, there is always a little bit of concern that it will take its toll on demand,’ said Phil Flynn of Price Futures Group. ‘Because this is a very popular airport in Europe, there are concerns that people will cancel vacations and the possibility that demand for jet fuel will fall.’OPEC`s secretary-general Abdalla el-Badri said in Vienna on Monday that 15 or 16 nations would join talks on output caps in Doha on Apr 17, Bloomberg News reported. Badri also said he hopes that prices have ‘bottomed,’ adding that he expects crude to see a ‘moderate’ bounce rather than reach previous high levels.Qatar’s oil ministry has invited Iran to the meeting, even as Tehran insists it is not ready to accept production limits. The prospect of an Iranian exemption has kept world crude prices under pressure, despite the increase in Iranian output so far being more than outweighed by a sharp fall in production by other OPEC members, notably Iraq.According to OPEC’s latest monthly report, Iran pumped out 3.1 million barrels per day of crude in February, up from 2.9 million in January. Overall production by the cartel fell by 175,000 bpd in February to an average of 32.28 million bpd, largely because of the steep drop in Iraqi output and smaller falls in Nigeria and the United Arab Emirates.Sydney-based CMC Markets analyst Michael McCarthy said traders do not expect much from the Qatar meeting. ‘I would be surprised if many people in the oil market are holding out much hope for this meeting,’ he told AFP.‘The levels of trust required getting so many different nations and companies to curtail their production, I don’t think is there. While it may add to the firm tone of the market, I don’t think it is a key driver.’